diff --git a/GUI/Model/Data/Data1DViewItem.h b/GUI/Model/Data/Data1DViewItem.h
index 5b3ebd3774da830cdcc8edd81343d90decf85833..babc4f0d733df4cff377e976bd34ec4b85a77a2d 100644
--- a/GUI/Model/Data/Data1DViewItem.h
+++ b/GUI/Model/Data/Data1DViewItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_DATA_DATA1DVIEWITEM_H
 #define BORNAGAIN_GUI_MODEL_DATA_DATA1DVIEWITEM_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include "GUI/Model/T0/SessionItem.h"
 
 class AmplitudeAxisItem;
diff --git a/GUI/Model/Data/DataItem.h b/GUI/Model/Data/DataItem.h
index 46deaaa60fbc14b4bdf4d47182fe761583e01bcc..d6664d11368ff77fa24a65f775726c58fd1a7f7f 100644
--- a/GUI/Model/Data/DataItem.h
+++ b/GUI/Model/Data/DataItem.h
@@ -16,7 +16,7 @@
 #define BORNAGAIN_GUI_MODEL_DATA_DATAITEM_H
 
 #include "Device/Data/OutputData.h"
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include "GUI/Model/IO/SaveLoadInterface.h"
 #include "GUI/Model/T0/SessionItem.h"
 #include <QDateTime>
diff --git a/GUI/Model/Data/IntensityDataItem.h b/GUI/Model/Data/IntensityDataItem.h
index 2271c704df8989cc4a3418e85e92f3036fe7e843..6ed52a45ef764a73e2860c81ff189764cb08d78e 100644
--- a/GUI/Model/Data/IntensityDataItem.h
+++ b/GUI/Model/Data/IntensityDataItem.h
@@ -16,7 +16,7 @@
 #define BORNAGAIN_GUI_MODEL_DATA_INTENSITYDATAITEM_H
 
 #include "GUI/Model/Data/DataItem.h"
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 
 class BasicAxisItem;
 class AmplitudeAxisItem;
diff --git a/GUI/Model/Fit/MinimizerItem.h b/GUI/Model/Fit/MinimizerItem.h
index cccb887d108ceef29f1f85f1faa94f1b77787796..dd0fb4ad65aa716b9676748fc1e06b64b591a974 100644
--- a/GUI/Model/Fit/MinimizerItem.h
+++ b/GUI/Model/Fit/MinimizerItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_FIT_MINIMIZERITEM_H
 #define BORNAGAIN_GUI_MODEL_FIT_MINIMIZERITEM_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include "GUI/Model/T0/SessionItem.h"
 #include "GUI/Model/Types/DoubleDescriptor.h"
 #include "GUI/Model/Types/UIntDescriptor.h"
diff --git a/GUI/Model/Group/DistributionItems.cpp b/GUI/Model/G0/DistributionItems.cpp
similarity index 99%
rename from GUI/Model/Group/DistributionItems.cpp
rename to GUI/Model/G0/DistributionItems.cpp
index 0765e962719e28bfb5dcd49710ce457cfdcd8c33..6c1424dc9588cc4611db84dd90e600d18079066c 100644
--- a/GUI/Model/Group/DistributionItems.cpp
+++ b/GUI/Model/G0/DistributionItems.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/DistributionItems.cpp
+//! @file      GUI/Model/G0/DistributionItems.cpp
 //! @brief     Implements class DistributionItem and several subclasses
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/DistributionItems.h"
-#include "GUI/Model/Group/GroupInfo.h"
+#include "GUI/Model/G0/DistributionItems.h"
+#include "GUI/Model/G2/GroupInfo.h"
 #include "GUI/Model/S4/RealLimitsItems.h"
 #include "Param/Distrib/Distributions.h"
 #include "Param/Distrib/RangedDistributions.h"
diff --git a/GUI/Model/Group/DistributionItems.h b/GUI/Model/G0/DistributionItems.h
similarity index 96%
rename from GUI/Model/Group/DistributionItems.h
rename to GUI/Model/G0/DistributionItems.h
index fe3f4c1897097bee30cb77661c153cafd474bb42..2d8b34e81c8bb989baf535457f74a12930e00693 100644
--- a/GUI/Model/Group/DistributionItems.h
+++ b/GUI/Model/G0/DistributionItems.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/DistributionItems.h
+//! @file      GUI/Model/G0/DistributionItems.h
 //! @brief     Defines class DistributionItem and several subclasses
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_DISTRIBUTIONITEMS_H
-#define BORNAGAIN_GUI_MODEL_GROUP_DISTRIBUTIONITEMS_H
+#ifndef BORNAGAIN_GUI_MODEL_G0_DISTRIBUTIONITEMS_H
+#define BORNAGAIN_GUI_MODEL_G0_DISTRIBUTIONITEMS_H
 
 #include "GUI/Model/T0/SessionItem.h"
 
@@ -207,4 +207,4 @@ public:
     void setRightWidth(double right_width);
 };
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_DISTRIBUTIONITEMS_H
+#endif // BORNAGAIN_GUI_MODEL_G0_DISTRIBUTIONITEMS_H
diff --git a/GUI/Model/Group/FilterPropertyProxy.cpp b/GUI/Model/G1/FilterPropertyProxy.cpp
similarity index 89%
rename from GUI/Model/Group/FilterPropertyProxy.cpp
rename to GUI/Model/G1/FilterPropertyProxy.cpp
index c76c843bf897e34228f2adb93fd79bab6e6a452e..ca14d163f33e40b5132f81e6bcbd29b34cb0f528 100644
--- a/GUI/Model/Group/FilterPropertyProxy.cpp
+++ b/GUI/Model/G1/FilterPropertyProxy.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/FilterPropertyProxy.cpp
+//! @file      GUI/Model/G1/FilterPropertyProxy.cpp
 //! @brief     Implements class FilterPropertyProxy
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,9 +12,9 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/FilterPropertyProxy.h"
-#include "GUI/Model/Group/GroupItem.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G1/FilterPropertyProxy.h"
+#include "GUI/Model/G3/GroupItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/Model/Types/VectorItem.h"
 #include "GUI/Util/SessionFlags.h"
diff --git a/GUI/Model/Group/FilterPropertyProxy.h b/GUI/Model/G1/FilterPropertyProxy.h
similarity index 84%
rename from GUI/Model/Group/FilterPropertyProxy.h
rename to GUI/Model/G1/FilterPropertyProxy.h
index faef02cad60700b70d06a84af0ed45dc7b213ddf..e7da0c0423664b77033c6bb2770da87e092b2ab3 100644
--- a/GUI/Model/Group/FilterPropertyProxy.h
+++ b/GUI/Model/G1/FilterPropertyProxy.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/FilterPropertyProxy.h
+//! @file      GUI/Model/G1/FilterPropertyProxy.h
 //! @brief     Defines class FilterPropertyProxy
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_FILTERPROPERTYPROXY_H
-#define BORNAGAIN_GUI_MODEL_GROUP_FILTERPROPERTYPROXY_H
+#ifndef BORNAGAIN_GUI_MODEL_G1_FILTERPROPERTYPROXY_H
+#define BORNAGAIN_GUI_MODEL_G1_FILTERPROPERTYPROXY_H
 
 #include <QSortFilterProxyModel>
 
@@ -41,4 +41,4 @@ private:
     int m_columns;
 };
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_FILTERPROPERTYPROXY_H
+#endif // BORNAGAIN_GUI_MODEL_G1_FILTERPROPERTYPROXY_H
diff --git a/GUI/Model/Group/GroupInfo.cpp b/GUI/Model/G2/GroupInfo.cpp
similarity index 96%
rename from GUI/Model/Group/GroupInfo.cpp
rename to GUI/Model/G2/GroupInfo.cpp
index 8103ea1cb24a50c032eb01649c59bbd3b0e22f08..5b54a0ebc4f1134bfec107ea038f56a5c50c4da4 100644
--- a/GUI/Model/Group/GroupInfo.cpp
+++ b/GUI/Model/G2/GroupInfo.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/GroupInfo.cpp
+//! @file      GUI/Model/G2/GroupInfo.cpp
 //! @brief     Defines class GroupInfo
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,7 +12,7 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/GroupInfo.h"
+#include "GUI/Model/G2/GroupInfo.h"
 #include "GUI/Util/Error.h"
 
 GroupInfo::GroupInfo(bool is_sorted) : is_sorted(is_sorted) {}
diff --git a/GUI/Model/Group/GroupInfo.h b/GUI/Model/G2/GroupInfo.h
similarity index 90%
rename from GUI/Model/Group/GroupInfo.h
rename to GUI/Model/G2/GroupInfo.h
index 0657ef5b6effa6a9701e68558a890b296daad7ac..684b76d7f31301f7e0f914fe58635441888e6c3b 100644
--- a/GUI/Model/Group/GroupInfo.h
+++ b/GUI/Model/G2/GroupInfo.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/GroupInfo.h
+//! @file      GUI/Model/G2/GroupInfo.h
 //! @brief     Defines class GroupInfo
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,10 +12,10 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_GROUPINFO_H
-#define BORNAGAIN_GUI_MODEL_GROUP_GROUPINFO_H
+#ifndef BORNAGAIN_GUI_MODEL_G2_GROUPINFO_H
+#define BORNAGAIN_GUI_MODEL_G2_GROUPINFO_H
 
-#include "GUI/Model/Group/ItemCatalog.h"
+#include "GUI/Model/G5/ItemCatalog.h"
 #include <QString>
 #include <QStringList>
 #include <QVector>
@@ -67,4 +67,4 @@ private:
     QVector<TypeAndLabel> m_info;
 };
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_GROUPINFO_H
+#endif // BORNAGAIN_GUI_MODEL_G2_GROUPINFO_H
diff --git a/GUI/Model/Group/GroupItem.cpp b/GUI/Model/G3/GroupItem.cpp
similarity index 96%
rename from GUI/Model/Group/GroupItem.cpp
rename to GUI/Model/G3/GroupItem.cpp
index c7c1fbe9de2f383e9258ef5f192efb7cfab69a74..372b279e016351a5cd376ce5f77b485d49f01d3c 100644
--- a/GUI/Model/Group/GroupItem.cpp
+++ b/GUI/Model/G3/GroupItem.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/GroupItem.cpp
+//! @file      GUI/Model/G3/GroupItem.cpp
 //! @brief     Implements class GroupItem
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,7 +12,7 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Util/ComboProperty.h"
 #include "GUI/Util/Error.h"
 
diff --git a/GUI/Model/Group/GroupItem.h b/GUI/Model/G3/GroupItem.h
similarity index 86%
rename from GUI/Model/Group/GroupItem.h
rename to GUI/Model/G3/GroupItem.h
index 78111836dea5f84330c594279d3b79f892841d1b..5774fe8e928e1c05ccced050e936a3c10fa88b0f 100644
--- a/GUI/Model/Group/GroupItem.h
+++ b/GUI/Model/G3/GroupItem.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/GroupItem.h
+//! @file      GUI/Model/G3/GroupItem.h
 //! @brief     Defines class GroupItem
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,10 +12,10 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_GROUPITEM_H
-#define BORNAGAIN_GUI_MODEL_GROUP_GROUPITEM_H
+#ifndef BORNAGAIN_GUI_MODEL_G3_GROUPITEM_H
+#define BORNAGAIN_GUI_MODEL_G3_GROUPITEM_H
 
-#include "GUI/Model/Group/GroupItemController.h"
+#include "GUI/Model/G4/GroupItemController.h"
 #include "GUI/Model/T0/SessionItem.h"
 #include <memory>
 
@@ -57,4 +57,4 @@ template <typename T> T* GroupItem::itemOfType() const
     return dynamic_cast<T*>(m_controller->getItemOfType(T::M_TYPE));
 }
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_GROUPITEM_H
+#endif // BORNAGAIN_GUI_MODEL_G3_GROUPITEM_H
diff --git a/GUI/Model/Group/GroupItemController.cpp b/GUI/Model/G4/GroupItemController.cpp
similarity index 95%
rename from GUI/Model/Group/GroupItemController.cpp
rename to GUI/Model/G4/GroupItemController.cpp
index ec6242973e0dbd27f88d67c3de702853fedfe5b0..6ead55eff3cf6bfecf50e9f8cf1c180d9f86aea0 100644
--- a/GUI/Model/Group/GroupItemController.cpp
+++ b/GUI/Model/G4/GroupItemController.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/GroupItemController.cpp
+//! @file      GUI/Model/G4/GroupItemController.cpp
 //! @brief     Implements class GroupItemController
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,9 +12,9 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/GroupItemController.h"
+#include "GUI/Model/G4/GroupItemController.h"
 
-#include "GUI/Model/Group/ItemFactory.h"
+#include "GUI/Model/G7/ItemFactory.h"
 #include "GUI/Model/T0/SessionItem.h"
 #include "GUI/Util/ComboProperty.h"
 #include <utility>
diff --git a/GUI/Model/Group/GroupItemController.h b/GUI/Model/G4/GroupItemController.h
similarity index 84%
rename from GUI/Model/Group/GroupItemController.h
rename to GUI/Model/G4/GroupItemController.h
index 2d5faa963405b59c3499903e5d7223f148c73bc7..a7f78593b360ed46a5dcef2d0aecfbd1ae6c7f8a 100644
--- a/GUI/Model/Group/GroupItemController.h
+++ b/GUI/Model/G4/GroupItemController.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/GroupItemController.h
+//! @file      GUI/Model/G4/GroupItemController.h
 //! @brief     Defines class GroupItemController
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,10 +12,10 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_GROUPITEMCONTROLLER_H
-#define BORNAGAIN_GUI_MODEL_GROUP_GROUPITEMCONTROLLER_H
+#ifndef BORNAGAIN_GUI_MODEL_G4_GROUPITEMCONTROLLER_H
+#define BORNAGAIN_GUI_MODEL_G4_GROUPITEMCONTROLLER_H
 
-#include "GUI/Model/Group/GroupInfo.h"
+#include "GUI/Model/G2/GroupInfo.h"
 #include <QStringList>
 #include <QVariant>
 
@@ -52,4 +52,4 @@ private:
     GroupInfo m_groupInfo;
 };
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_GROUPITEMCONTROLLER_H
+#endif // BORNAGAIN_GUI_MODEL_G4_GROUPITEMCONTROLLER_H
diff --git a/GUI/Model/Group/ItemCatalog.cpp b/GUI/Model/G5/ItemCatalog.cpp
similarity index 97%
rename from GUI/Model/Group/ItemCatalog.cpp
rename to GUI/Model/G5/ItemCatalog.cpp
index 6698bb7b022a03e9435ef235662b6dc4cb006a4e..52e82597dcaea9ff048b0efae08f3682d8e04149 100644
--- a/GUI/Model/Group/ItemCatalog.cpp
+++ b/GUI/Model/G5/ItemCatalog.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/ItemCatalog.cpp
+//! @file      GUI/Model/G5/ItemCatalog.cpp
 //! @brief     Implements class ItemCatalog
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,7 +12,7 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/ItemCatalog.h"
+#include "GUI/Model/G5/ItemCatalog.h"
 #include "Base/Util/Assert.h"
 #include "GUI/Model/Data/Data1DViewItem.h"
 #include "GUI/Model/Data/DataProperties.h"
@@ -29,7 +29,7 @@
 #include "GUI/Model/Fit/FitSuiteItem.h"
 #include "GUI/Model/Fit/MinimizerItem.h"
 #include "GUI/Model/Fit/ParameterTreeItems.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Instrument/BackgroundItems.h"
 #include "GUI/Model/Instrument/BeamAngleItems.h"
 #include "GUI/Model/Instrument/BeamWavelengthItem.h"
diff --git a/GUI/Model/Group/ItemCatalog.h b/GUI/Model/G5/ItemCatalog.h
similarity index 88%
rename from GUI/Model/Group/ItemCatalog.h
rename to GUI/Model/G5/ItemCatalog.h
index 52a6a53b8d25dcdfcf564d2ad76896ab813abe9a..cbb8649570c75b4133368d0294afaa64d0966a55 100644
--- a/GUI/Model/Group/ItemCatalog.h
+++ b/GUI/Model/G5/ItemCatalog.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/ItemCatalog.h
+//! @file      GUI/Model/G5/ItemCatalog.h
 //! @brief     Defines class ItemCatalog
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_ITEMCATALOG_H
-#define BORNAGAIN_GUI_MODEL_GROUP_ITEMCATALOG_H
+#ifndef BORNAGAIN_GUI_MODEL_G5_ITEMCATALOG_H
+#define BORNAGAIN_GUI_MODEL_G5_ITEMCATALOG_H
 
 #include "Base/Util/IFactory.h"
 #include <QMap>
@@ -55,4 +55,4 @@ private:
 };
 
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_ITEMCATALOG_H
+#endif // BORNAGAIN_GUI_MODEL_G5_ITEMCATALOG_H
diff --git a/GUI/Model/Group/PropertyItem.cpp b/GUI/Model/G6/PropertyItem.cpp
similarity index 87%
rename from GUI/Model/Group/PropertyItem.cpp
rename to GUI/Model/G6/PropertyItem.cpp
index 63c5b1c75474882128c64c9982b4b8874db769e0..8652ce2867f3cd0bfd28fb6f47706a938aa0715a 100644
--- a/GUI/Model/Group/PropertyItem.cpp
+++ b/GUI/Model/G6/PropertyItem.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/PropertyItem.cpp
+//! @file      GUI/Model/G6/PropertyItem.cpp
 //! @brief     Implements class PropertyItem
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,6 +12,6 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 
 PropertyItem::PropertyItem() : SessionItem(M_TYPE) {}
diff --git a/GUI/Model/Group/PropertyItem.h b/GUI/Model/G6/PropertyItem.h
similarity index 78%
rename from GUI/Model/Group/PropertyItem.h
rename to GUI/Model/G6/PropertyItem.h
index 8cf65dedf8910b3ecaef81a0823baea3aeb316eb..6c11af82210e79825b2c108599966d16247a49f4 100644
--- a/GUI/Model/Group/PropertyItem.h
+++ b/GUI/Model/G6/PropertyItem.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/PropertyItem.h
+//! @file      GUI/Model/G6/PropertyItem.h
 //! @brief     Defines class PropertyItem
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_PROPERTYITEM_H
-#define BORNAGAIN_GUI_MODEL_GROUP_PROPERTYITEM_H
+#ifndef BORNAGAIN_GUI_MODEL_G6_PROPERTYITEM_H
+#define BORNAGAIN_GUI_MODEL_G6_PROPERTYITEM_H
 
 #include "GUI/Model/T0/SessionItem.h"
 
@@ -24,4 +24,4 @@ public:
     PropertyItem();
 };
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_PROPERTYITEM_H
+#endif // BORNAGAIN_GUI_MODEL_G6_PROPERTYITEM_H
diff --git a/GUI/Model/Group/ItemFactory.cpp b/GUI/Model/G7/ItemFactory.cpp
similarity index 88%
rename from GUI/Model/Group/ItemFactory.cpp
rename to GUI/Model/G7/ItemFactory.cpp
index fee6a7403544f983b1861bfb234dbee9117e092e..5fbeca5bf6d6dea0e19c8eadeedb50f12d233920 100644
--- a/GUI/Model/Group/ItemFactory.cpp
+++ b/GUI/Model/G7/ItemFactory.cpp
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/ItemFactory.cpp
+//! @file      GUI/Model/G7/ItemFactory.cpp
 //! @brief     Implements class ItemFactory
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/ItemFactory.h"
-#include "GUI/Model/Group/ItemCatalog.h"
+#include "GUI/Model/G7/ItemFactory.h"
+#include "GUI/Model/G5/ItemCatalog.h"
 #include "GUI/Model/T0/SessionItem.h"
 
 SessionItem* GUI::Model::ItemFactory::CreateItem(const QString& model_name, SessionItem* parent)
diff --git a/GUI/Model/Group/ItemFactory.h b/GUI/Model/G7/ItemFactory.h
similarity index 86%
rename from GUI/Model/Group/ItemFactory.h
rename to GUI/Model/G7/ItemFactory.h
index 9af2541e6183b1c600613a36f709344b4c23b907..e0ae00ed947f0a92e94a50db23ac25d55272d90a 100644
--- a/GUI/Model/Group/ItemFactory.h
+++ b/GUI/Model/G7/ItemFactory.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/ItemFactory.h
+//! @file      GUI/Model/G7/ItemFactory.h
 //! @brief     Defines namespace GUI::Model::ItemFactory
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,8 +12,8 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_ITEMFACTORY_H
-#define BORNAGAIN_GUI_MODEL_GROUP_ITEMFACTORY_H
+#ifndef BORNAGAIN_GUI_MODEL_G7_ITEMFACTORY_H
+#define BORNAGAIN_GUI_MODEL_G7_ITEMFACTORY_H
 
 #include <QString>
 
@@ -38,4 +38,4 @@ template <typename ItemType> ItemType* CreateItem(SessionItem* parent)
 
 } // namespace GUI::Model::ItemFactory
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_ITEMFACTORY_H
+#endif // BORNAGAIN_GUI_MODEL_G7_ITEMFACTORY_H
diff --git a/GUI/Model/Group/SelectionDescriptor.h b/GUI/Model/G8/SelectionDescriptor.h
similarity index 95%
rename from GUI/Model/Group/SelectionDescriptor.h
rename to GUI/Model/G8/SelectionDescriptor.h
index c439e52081936f568f528d9fddb13f1a94054e7e..5af8aabc627fb02754b208ef12ceb7ea64e50cf3 100644
--- a/GUI/Model/Group/SelectionDescriptor.h
+++ b/GUI/Model/G8/SelectionDescriptor.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/SelectionDescriptor.h
+//! @file      GUI/Model/G8/SelectionDescriptor.h
 //! @brief     Defines class SelectionDescriptor
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,10 +12,10 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_SELECTIONDESCRIPTOR_H
-#define BORNAGAIN_GUI_MODEL_GROUP_SELECTIONDESCRIPTOR_H
+#ifndef BORNAGAIN_GUI_MODEL_G8_SELECTIONDESCRIPTOR_H
+#define BORNAGAIN_GUI_MODEL_G8_SELECTIONDESCRIPTOR_H
 
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Util/ComboProperty.h"
 #include <QString>
 #include <QStringList>
@@ -129,4 +129,4 @@ const QString& tooltip, const T* ppItem)
 }
 */
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_SELECTIONDESCRIPTOR_H
+#endif // BORNAGAIN_GUI_MODEL_G8_SELECTIONDESCRIPTOR_H
diff --git a/GUI/Model/Group/SelectionProperty.h b/GUI/Model/G9/SelectionProperty.h
similarity index 84%
rename from GUI/Model/Group/SelectionProperty.h
rename to GUI/Model/G9/SelectionProperty.h
index e017f3b4941107cb633c17b25507a9929f70b521..e8213f8b7455b8c14bb01783f59cf0a0df8a021b 100644
--- a/GUI/Model/Group/SelectionProperty.h
+++ b/GUI/Model/G9/SelectionProperty.h
@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit reflection and scattering
 //
-//! @file      GUI/Model/Group/SelectionProperty.h
+//! @file      GUI/Model/G9/SelectionProperty.h
 //! @brief     Defines class SelectionProperty
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -12,10 +12,10 @@
 //
 //  ************************************************************************************************
 
-#ifndef BORNAGAIN_GUI_MODEL_GROUP_SELECTIONPROPERTY_H
-#define BORNAGAIN_GUI_MODEL_GROUP_SELECTIONPROPERTY_H
+#ifndef BORNAGAIN_GUI_MODEL_G9_SELECTIONPROPERTY_H
+#define BORNAGAIN_GUI_MODEL_G9_SELECTIONPROPERTY_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 
 // #baMigration docu
 template <typename T> class SelectionProperty {
@@ -53,4 +53,4 @@ private:
 };
 
 
-#endif // BORNAGAIN_GUI_MODEL_GROUP_SELECTIONPROPERTY_H
+#endif // BORNAGAIN_GUI_MODEL_G9_SELECTIONPROPERTY_H
diff --git a/GUI/Model/Instrument/BeamDistributionItem.cpp b/GUI/Model/Instrument/BeamDistributionItem.cpp
index 754941dffacb375aef524952c4343f5bf19c9fa5..76a48a7eac59fb32708ede427603229e24779363 100644
--- a/GUI/Model/Instrument/BeamDistributionItem.cpp
+++ b/GUI/Model/Instrument/BeamDistributionItem.cpp
@@ -13,7 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/Model/Instrument/BeamDistributionItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/S4/RealLimitsItems.h"
 #include "Param/Distrib/Distributions.h"
 
diff --git a/GUI/Model/Instrument/BeamDistributionItem.h b/GUI/Model/Instrument/BeamDistributionItem.h
index 2c23943cf28737d6070a35c4141f1bd8c81baf9e..178c9bc5e48883edcba444df79e70eb4fbcc6a9d 100644
--- a/GUI/Model/Instrument/BeamDistributionItem.h
+++ b/GUI/Model/Instrument/BeamDistributionItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_INSTRUMENT_BEAMDISTRIBUTIONITEM_H
 #define BORNAGAIN_GUI_MODEL_INSTRUMENT_BEAMDISTRIBUTIONITEM_H
 
-#include "GUI/Model/Group/DistributionItems.h"
+#include "GUI/Model/G0/DistributionItems.h"
 #include "GUI/Model/Instrument/ItemWithDistribution.h"
 #include "Param/Distrib/ParameterDistribution.h"
 
diff --git a/GUI/Model/Instrument/BeamItems.cpp b/GUI/Model/Instrument/BeamItems.cpp
index 83e16707f47b1eefc838b2942995d595a8a281b9..3a939fa7a814a5f5e752b8fbb1c9fe8beddea7cc 100644
--- a/GUI/Model/Instrument/BeamItems.cpp
+++ b/GUI/Model/Instrument/BeamItems.cpp
@@ -17,7 +17,7 @@
 #include "Base/Const/Units.h"
 #include "Device/Beam/Beam.h"
 #include "GUI/Model/Data/PointwiseAxisItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/Instrument/BeamAngleItems.h"
 #include "GUI/Model/Instrument/BeamWavelengthItem.h"
 #include "GUI/Model/Instrument/FootprintItems.h"
diff --git a/GUI/Model/Instrument/DetectorItems.cpp b/GUI/Model/Instrument/DetectorItems.cpp
index 770a2ccd632ee43ba0be5a5262e7e177f0c5790b..669c268d5bc55b9bf5f81ddad1be0015dbfc8107 100644
--- a/GUI/Model/Instrument/DetectorItems.cpp
+++ b/GUI/Model/Instrument/DetectorItems.cpp
@@ -17,7 +17,7 @@
 #include "Device/Mask/IShape2D.h"
 #include "Device/Resolution/ResolutionFunction2DGaussian.h"
 #include "GUI/Model/Data/MaskItems.h"
-#include "GUI/Model/Group/GroupInfo.h"
+#include "GUI/Model/G2/GroupInfo.h"
 #include "GUI/Model/Instrument/ResolutionFunctionItems.h"
 #include "GUI/Model/Instrument/SphericalDetectorItem.h"
 #include "GUI/Model/Session/SessionModel.h"
diff --git a/GUI/Model/Instrument/InstrumentItems.cpp b/GUI/Model/Instrument/InstrumentItems.cpp
index 8bb0372f5d4341a7edaad56d2cc9b34761d87912..08d7bb03bb424dd7e1171a4a339a54c82fa98bed 100644
--- a/GUI/Model/Instrument/InstrumentItems.cpp
+++ b/GUI/Model/Instrument/InstrumentItems.cpp
@@ -23,7 +23,7 @@
 #include "Device/Detector/SphericalDetector.h"
 #include "GUI/Model/Data/PointwiseAxisItem.h"
 #include "GUI/Model/Data/RealDataItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/IO/ItemFileNameUtils.h"
 #include "GUI/Model/Instrument/BackgroundItems.h"
 #include "GUI/Model/Instrument/BeamWavelengthItem.h"
diff --git a/GUI/Model/Instrument/InstrumentModel.cpp b/GUI/Model/Instrument/InstrumentModel.cpp
index 2d8d0e8de23951e03a4d0269bea311f9f2d211ec..58642a77e7b6b6ccf1938985e50c7b352a9d9515 100644
--- a/GUI/Model/Instrument/InstrumentModel.cpp
+++ b/GUI/Model/Instrument/InstrumentModel.cpp
@@ -14,7 +14,7 @@
 
 #include "GUI/Model/Instrument/InstrumentModel.h"
 #include "GUI/Model/Data/PointwiseAxisItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/Instrument/InstrumentItems.h"
 #include "GUI/Model/S3/SessionXML.h"
 #include "GUI/Util/String.h"
diff --git a/GUI/Model/Instrument/SpecularBeamInclinationItem.cpp b/GUI/Model/Instrument/SpecularBeamInclinationItem.cpp
index 039d794d4224ae3a267c2efa78971351c1186745..ab829f6b74c6264afdf552f02ded1c3658062efc 100644
--- a/GUI/Model/Instrument/SpecularBeamInclinationItem.cpp
+++ b/GUI/Model/Instrument/SpecularBeamInclinationItem.cpp
@@ -15,7 +15,7 @@
 #include "GUI/Model/Instrument/SpecularBeamInclinationItem.h"
 #include "Base/Const/Units.h"
 #include "GUI/Model/Data/PointwiseAxisItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 
 namespace {
 
diff --git a/GUI/Model/Job/ParameterTreeUtils.cpp b/GUI/Model/Job/ParameterTreeUtils.cpp
index a2d324ad08022dfaa02b72e725e2a22300f278c8..5d6f8fedda90e7ca6cc56d888df5e6efca7dc451 100644
--- a/GUI/Model/Job/ParameterTreeUtils.cpp
+++ b/GUI/Model/Job/ParameterTreeUtils.cpp
@@ -14,7 +14,7 @@
 
 #include "GUI/Model/Job/ParameterTreeUtils.h"
 #include "GUI/Model/Fit/ParameterTreeItems.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Instrument/InstrumentItems.h"
 #include "GUI/Model/Job/JobItem.h"
 #include "GUI/Model/Material/MaterialItem.h"
diff --git a/GUI/Model/S1/Serializer.h b/GUI/Model/S1/Serializer.h
index e29b39fdd5b4e33c1c43e9eeea67c3b8ac251a02..8130bb89867b7849f1feb6b5e0b1e88e0c685d64 100644
--- a/GUI/Model/S1/Serializer.h
+++ b/GUI/Model/S1/Serializer.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_S1_SERIALIZER_H
 #define BORNAGAIN_GUI_MODEL_S1_SERIALIZER_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Types/DoubleDescriptor.h"
 #include <QXmlStreamWriter> // used in every including file
 
diff --git a/GUI/Model/S3/SessionXML.cpp b/GUI/Model/S3/SessionXML.cpp
index 825ac27e713a064c1a6229865340f44c469b5ffd..96a373baed6b5de7f66b0d78dfa9f1f011a1a26f 100644
--- a/GUI/Model/S3/SessionXML.cpp
+++ b/GUI/Model/S3/SessionXML.cpp
@@ -13,7 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/Model/S3/SessionXML.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/Material/MaterialItem.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/Util/ComboProperty.h"
diff --git a/GUI/Model/S3/SessionXML.h b/GUI/Model/S3/SessionXML.h
index 3a0a3f5f44e48e6bd06a1cce5ac38bc81f30625a..4ce3f445f5267e460b83d326b73cc842a8f6232f 100644
--- a/GUI/Model/S3/SessionXML.h
+++ b/GUI/Model/S3/SessionXML.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_S3_SESSIONXML_H
 #define BORNAGAIN_GUI_MODEL_S3_SESSIONXML_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Types/DoubleDescriptor.h"
 #include <QVariant>
 #include <QXmlStreamWriter> // used in every including file
diff --git a/GUI/Model/Sample/InterferenceItems.h b/GUI/Model/Sample/InterferenceItems.h
index 8fe2b492bd43629d812c9209a9bc24577b2420e3..0ef45eab7849d754e4feb05ae18d4c1124409d70 100644
--- a/GUI/Model/Sample/InterferenceItems.h
+++ b/GUI/Model/Sample/InterferenceItems.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SAMPLE_INTERFERENCEITEMS_H
 #define BORNAGAIN_GUI_MODEL_SAMPLE_INTERFERENCEITEMS_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Sample/FTDecayFunctionItems.h"
 #include "GUI/Model/Sample/FTDistributionItems.h"
 #include "GUI/Model/Sample/Lattice2DItems.h"
diff --git a/GUI/Model/Sample/ItemWithParticles.h b/GUI/Model/Sample/ItemWithParticles.h
index 3dd5fa542752b73ff35bc6b19e1411cc60e06cde..38e022bc96bff65150e4786ca5542e628e9f2615 100644
--- a/GUI/Model/Sample/ItemWithParticles.h
+++ b/GUI/Model/Sample/ItemWithParticles.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SAMPLE_ITEMWITHPARTICLES_H
 #define BORNAGAIN_GUI_MODEL_SAMPLE_ITEMWITHPARTICLES_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Sample/RotationItems.h"
 #include "GUI/Model/Types/DoubleProperty.h"
 #include "GUI/Model/Types/VectorProperty.h"
diff --git a/GUI/Model/Sample/LayerItem.h b/GUI/Model/Sample/LayerItem.h
index f00cfb2f0b233a24ae478dedf89d62bd1c84d618..2630ab9e874ddc6662ccf3bae02da82df751de89 100644
--- a/GUI/Model/Sample/LayerItem.h
+++ b/GUI/Model/Sample/LayerItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SAMPLE_LAYERITEM_H
 #define BORNAGAIN_GUI_MODEL_SAMPLE_LAYERITEM_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include "GUI/Model/Sample/ItemWithMaterial.h"
 #include "GUI/Model/Sample/LayerRoughnessItems.h"
 #include "GUI/Model/Types/DoubleProperty.h"
diff --git a/GUI/Model/Sample/MesoCrystalItem.h b/GUI/Model/Sample/MesoCrystalItem.h
index 2273f7beead8f5efd9ebcc2336213751eb491bd8..32d4bdf34852e350b4106e4962834691ad546e80 100644
--- a/GUI/Model/Sample/MesoCrystalItem.h
+++ b/GUI/Model/Sample/MesoCrystalItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SAMPLE_MESOCRYSTALITEM_H
 #define BORNAGAIN_GUI_MODEL_SAMPLE_MESOCRYSTALITEM_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Sample/FormFactorItems.h"
 #include "GUI/Model/Sample/ItemWithParticles.h"
 #include "GUI/Model/Types/VectorProperty.h"
diff --git a/GUI/Model/Sample/ParticleItem.h b/GUI/Model/Sample/ParticleItem.h
index f62092de8e0378c502038a89fe7b1ea79a1c3166..0fd53e1943d96d7bd88805386a1724b73c2453b8 100644
--- a/GUI/Model/Sample/ParticleItem.h
+++ b/GUI/Model/Sample/ParticleItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SAMPLE_PARTICLEITEM_H
 #define BORNAGAIN_GUI_MODEL_SAMPLE_PARTICLEITEM_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Sample/FormFactorItems.h"
 #include "GUI/Model/Sample/ItemWithMaterial.h"
 #include "GUI/Model/Sample/ItemWithParticles.h"
diff --git a/GUI/Model/Sample/ParticleLayoutItem.h b/GUI/Model/Sample/ParticleLayoutItem.h
index b5789c263457fbfe9d6cf2daba5974c1a55e27b9..65789d32f36394dd10dea0765e956e5f4db446cd 100644
--- a/GUI/Model/Sample/ParticleLayoutItem.h
+++ b/GUI/Model/Sample/ParticleLayoutItem.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SAMPLE_PARTICLELAYOUTITEM_H
 #define BORNAGAIN_GUI_MODEL_SAMPLE_PARTICLELAYOUTITEM_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Sample/InterferenceItems.h"
 #include "GUI/Model/Types/DoubleProperty.h"
 #include <QUuid>
diff --git a/GUI/Model/Session/SessionModel.cpp b/GUI/Model/Session/SessionModel.cpp
index 69eb69f842ddfd03513134db41ad05c4ab0464b5..e9d3e77816e3ef865af984c7471587d2f3c8961e 100644
--- a/GUI/Model/Session/SessionModel.cpp
+++ b/GUI/Model/Session/SessionModel.cpp
@@ -13,7 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/Model/Session/SessionModel.h"
-#include "GUI/Model/Group/ItemFactory.h"
+#include "GUI/Model/G7/ItemFactory.h"
 #include "GUI/Model/Material/MaterialItem.h"
 #include "GUI/Model/T0/SessionItem.h"
 #include "GUI/Model/S3/SessionXML.h"
diff --git a/GUI/Model/Session/SessionModel.h b/GUI/Model/Session/SessionModel.h
index 4442b692ee315a7272b33ac52545696b8ead1906..0973b0970ba2d9ba5447bf22362a43c061eecb6a 100644
--- a/GUI/Model/Session/SessionModel.h
+++ b/GUI/Model/Session/SessionModel.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_MODEL_SESSION_SESSIONMODEL_H
 #define BORNAGAIN_GUI_MODEL_SESSION_SESSIONMODEL_H
 
-#include "GUI/Model/Group/SelectionProperty.h"
+#include "GUI/Model/G9/SelectionProperty.h"
 #include "GUI/Model/Types/DoubleDescriptor.h"
 #include <heinz/Complex.h>
 #include <heinz/Vectors3D.h>
diff --git a/GUI/Model/T0/SessionItem.cpp b/GUI/Model/T0/SessionItem.cpp
index 4b7c966aa99525197dec9d54e41f639e2b5fde71..64ecca2404c49dc8cc903f4c4c1a898633dcf009 100644
--- a/GUI/Model/T0/SessionItem.cpp
+++ b/GUI/Model/T0/SessionItem.cpp
@@ -12,9 +12,9 @@
 //
 //  ************************************************************************************************
 
-#include "GUI/Model/Group/GroupItem.h"
-#include "GUI/Model/Group/ItemFactory.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G3/GroupItem.h"
+#include "GUI/Model/G7/ItemFactory.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/Model/T2/SessionItemData.h"
 #include "GUI/Util/SessionFlags.h"
diff --git a/GUI/View/Fit/FitParameterWidget.cpp b/GUI/View/Fit/FitParameterWidget.cpp
index 0415ad4bdd2473869f87baef979a951dc87194f9..d35bd9341146813fc93556542c4da1fc87714cfb 100644
--- a/GUI/View/Fit/FitParameterWidget.cpp
+++ b/GUI/View/Fit/FitParameterWidget.cpp
@@ -20,7 +20,7 @@
 #include "GUI/Model/Fit/FitParameterModel.h"
 #include "GUI/Model/Fit/FitSuiteItem.h"
 #include "GUI/Model/Fit/ParameterTreeItems.h"
-#include "GUI/Model/Group/FilterPropertyProxy.h"
+#include "GUI/Model/G1/FilterPropertyProxy.h"
 #include "GUI/Model/Job/JobItem.h"
 #include "GUI/Model/Job/JobModel.h"
 #include "GUI/View/Fit/FitParameterDelegate.h"
diff --git a/GUI/View/Fit/MinimizerSettingsWidget.h b/GUI/View/Fit/MinimizerSettingsWidget.h
index 392645dfa8503ea6f34751b2c23338fc724262bf..685e9ed5958e9cce1751571f3d22ce9ec44e2997 100644
--- a/GUI/View/Fit/MinimizerSettingsWidget.h
+++ b/GUI/View/Fit/MinimizerSettingsWidget.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_VIEW_FIT_MINIMIZERSETTINGSWIDGET_H
 #define BORNAGAIN_GUI_VIEW_FIT_MINIMIZERSETTINGSWIDGET_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include <QList>
 #include <QWidget>
 #include <functional>
diff --git a/GUI/View/Instrument/DistributionEditor.cpp b/GUI/View/Instrument/DistributionEditor.cpp
index 76dd1d29abc9a897b72eac8692d557471e04f742..324f0b0a4b382b9095c0611557587bae4108e4b3 100644
--- a/GUI/View/Instrument/DistributionEditor.cpp
+++ b/GUI/View/Instrument/DistributionEditor.cpp
@@ -13,7 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/View/Instrument/DistributionEditor.h"
-#include "GUI/Model/Group/DistributionItems.h"
+#include "GUI/Model/G0/DistributionItems.h"
 #include "GUI/Model/Instrument/ItemWithDistribution.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/View/Instrument/DistributionForms.h"
diff --git a/GUI/View/Instrument/DistributionForms.cpp b/GUI/View/Instrument/DistributionForms.cpp
index 416a883ce28d35c2853c7a03fd7bb58a815fddf2..825693b991d0d54e3fba84fff59d35926f7c4dad 100644
--- a/GUI/View/Instrument/DistributionForms.cpp
+++ b/GUI/View/Instrument/DistributionForms.cpp
@@ -13,7 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/View/Instrument/DistributionForms.h"
-#include "GUI/Model/Group/DistributionItems.h"
+#include "GUI/Model/G0/DistributionItems.h"
 #include "GUI/Model/Instrument/ItemWithDistribution.h"
 #include "GUI/View/Instrument/DistributionEditor.h"
 #include "GUI/View/PropertyEditor/ScientificSpinBox.h"
diff --git a/GUI/View/Instrument/DistributionPlot.cpp b/GUI/View/Instrument/DistributionPlot.cpp
index 1e5f9f58f0308387991b8312bf185a2540f44dfb..f80004c51d8dc1c4c3339906c173259e806db69f 100644
--- a/GUI/View/Instrument/DistributionPlot.cpp
+++ b/GUI/View/Instrument/DistributionPlot.cpp
@@ -13,7 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/View/Instrument/DistributionPlot.h"
-#include "GUI/Model/Group/DistributionItems.h"
+#include "GUI/Model/G0/DistributionItems.h"
 #include "GUI/Model/S4/RealLimitsItems.h"
 #include "GUI/View/Info/CautionSign.h"
 #include "Param/Distrib/Distributions.h"
diff --git a/GUI/View/Instrument/InclinationAnglesEditor.cpp b/GUI/View/Instrument/InclinationAnglesEditor.cpp
index f9aa0b440080f30a4855af7deb6d0a98dbd00f51..357b14197884de02e1428601753236ab170fddf6 100644
--- a/GUI/View/Instrument/InclinationAnglesEditor.cpp
+++ b/GUI/View/Instrument/InclinationAnglesEditor.cpp
@@ -14,7 +14,7 @@
 
 #include "GUI/View/Instrument/InclinationAnglesEditor.h"
 #include "GUI/Model/Data/PointwiseAxisItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/Instrument/SpecularBeamInclinationItem.h"
 #include "GUI/View/Instrument/DistributionEditor.h"
 #include "GUI/View/Instrument/SphericalAxisEditor.h"
diff --git a/GUI/View/Mask/MaskGraphicsScene.cpp b/GUI/View/Mask/MaskGraphicsScene.cpp
index 3278749fef38b1619a8c1f9d0a41371fdbd00199..c6cad6c096b285e27c62862512776b0b70a6385e 100644
--- a/GUI/View/Mask/MaskGraphicsScene.cpp
+++ b/GUI/View/Mask/MaskGraphicsScene.cpp
@@ -15,8 +15,8 @@
 #include "GUI/View/Mask/MaskGraphicsScene.h"
 #include "GUI/Model/Data/MaskItems.h"
 #include "GUI/Model/Data/ProjectionItems.h"
-#include "GUI/Model/Group/GroupItem.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G3/GroupItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/Util/Error.h"
 #include "GUI/View/Mask/ColorMapSceneAdaptor.h"
diff --git a/GUI/View/PlotUtil/IntensityDataPropertyWidget.h b/GUI/View/PlotUtil/IntensityDataPropertyWidget.h
index e602276b3b9fcb42c1f1db3f268dd005a9ad74a0..ceab27023ba4a57cf94bb925ec2861ae5149c281 100644
--- a/GUI/View/PlotUtil/IntensityDataPropertyWidget.h
+++ b/GUI/View/PlotUtil/IntensityDataPropertyWidget.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_VIEW_PLOTUTIL_INTENSITYDATAPROPERTYWIDGET_H
 #define BORNAGAIN_GUI_VIEW_PLOTUTIL_INTENSITYDATAPROPERTYWIDGET_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include <QList>
 #include <QString>
 #include <QWidget>
diff --git a/GUI/View/PropertyEditor/SpecularDataPropertyWidget.h b/GUI/View/PropertyEditor/SpecularDataPropertyWidget.h
index 380f3cb1943b11f1757150e33ec5296da02e0fc1..e113239bebcde82f658a35822035d92fc807423f 100644
--- a/GUI/View/PropertyEditor/SpecularDataPropertyWidget.h
+++ b/GUI/View/PropertyEditor/SpecularDataPropertyWidget.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_VIEW_PROPERTYEDITOR_SPECULARDATAPROPERTYWIDGET_H
 #define BORNAGAIN_GUI_VIEW_PROPERTYEDITOR_SPECULARDATAPROPERTYWIDGET_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include <QList>
 #include <QString>
 #include <QWidget>
diff --git a/GUI/View/SampleDesigner/FormLayouter.h b/GUI/View/SampleDesigner/FormLayouter.h
index 23475231ed58043044881f7dda7c18c11807606d..c1d91afc019ee50dcc020c56a417b3e2a38d3910 100644
--- a/GUI/View/SampleDesigner/FormLayouter.h
+++ b/GUI/View/SampleDesigner/FormLayouter.h
@@ -15,7 +15,7 @@
 #ifndef BORNAGAIN_GUI_VIEW_SAMPLEDESIGNER_FORMLAYOUTER_H
 #define BORNAGAIN_GUI_VIEW_SAMPLEDESIGNER_FORMLAYOUTER_H
 
-#include "GUI/Model/Group/SelectionDescriptor.h"
+#include "GUI/Model/G8/SelectionDescriptor.h"
 #include "GUI/View/SampleDesigner/SelectionContainerForm.h"
 #include <QFormLayout>
 
diff --git a/Tests/Unit/GUI/TestAxesItems.cpp b/Tests/Unit/GUI/TestAxesItems.cpp
index 5169307d595a951b65e2520619b20932f890fcf8..2da7ccc3b2e5ddbc8e7f1f5ba02235dc26fd8b97 100644
--- a/Tests/Unit/GUI/TestAxesItems.cpp
+++ b/Tests/Unit/GUI/TestAxesItems.cpp
@@ -3,7 +3,7 @@
 #include "Base/Const/Units.h"
 #include "GUI/Model/Data/AxesItems.h"
 #include "GUI/Model/From/FromDomain.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Util/Error.h"
 #include "Tests/GTestWrapper/google_test.h"
 
diff --git a/Tests/Unit/GUI/TestGroupItem.cpp b/Tests/Unit/GUI/TestGroupItem.cpp
index 6285735b56575423c109f8638f18279734340957..475a4edd24ea08079218669ba706750cbbdcfc0d 100644
--- a/Tests/Unit/GUI/TestGroupItem.cpp
+++ b/Tests/Unit/GUI/TestGroupItem.cpp
@@ -1,5 +1,5 @@
-#include "GUI/Model/Group/DistributionItems.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G0/DistributionItems.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/Sample/FormFactorItems.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/Util/ComboProperty.h"
diff --git a/Tests/Unit/GUI/TestSavingSpecularData.cpp b/Tests/Unit/GUI/TestSavingSpecularData.cpp
index ed83ce08a614fc72d9ae31d5fd88de2faec53c4c..75781d52c41ec0458da6e8378c26bf0204484b9d 100644
--- a/Tests/Unit/GUI/TestSavingSpecularData.cpp
+++ b/Tests/Unit/GUI/TestSavingSpecularData.cpp
@@ -3,7 +3,7 @@
 #include "GUI/Model/Data/ApplicationModels.h"
 #include "GUI/Model/Data/IntensityDataItem.h"
 #include "GUI/Model/Data/PointwiseAxisItem.h"
-#include "GUI/Model/Group/GroupItem.h"
+#include "GUI/Model/G3/GroupItem.h"
 #include "GUI/Model/IO/ItemFileNameUtils.h"
 #include "GUI/Model/IO/ProjectUtils.h"
 #include "GUI/Model/Instrument/InstrumentItems.h"
diff --git a/Tests/Unit/GUI/TestSessionItemUtils.cpp b/Tests/Unit/GUI/TestSessionItemUtils.cpp
index e47f869695a004964939d5318e55beae0f1e834c..85bd3ba9afad72c4b2cfdf030109379a56198dc0 100644
--- a/Tests/Unit/GUI/TestSessionItemUtils.cpp
+++ b/Tests/Unit/GUI/TestSessionItemUtils.cpp
@@ -1,4 +1,4 @@
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Session/SessionModel.h"
 #include "GUI/Model/Types/VectorItem.h"
 #include "GUI/Util/ComboProperty.h"
diff --git a/Tests/Unit/GUI/TestSessionModel.cpp b/Tests/Unit/GUI/TestSessionModel.cpp
index aa00013a0f45432a3e9368a50a6c523df51ea087..363906b15370c6a24eeba0fd3063c71c87b40d9f 100644
--- a/Tests/Unit/GUI/TestSessionModel.cpp
+++ b/Tests/Unit/GUI/TestSessionModel.cpp
@@ -1,5 +1,5 @@
 #include "GUI/Model/Data/MaskItems.h"
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Instrument/InstrumentItems.h"
 #include "GUI/Model/Instrument/InstrumentModel.h"
 #include "GUI/Model/Job/JobItem.h"
diff --git a/Tests/Unit/GUI/TestSessionXML.cpp b/Tests/Unit/GUI/TestSessionXML.cpp
index 68c4b7e79fe14453d65c7e49907588166939e847..45f3deb6a2afe1ac852f62f4f0f669af301e9824 100644
--- a/Tests/Unit/GUI/TestSessionXML.cpp
+++ b/Tests/Unit/GUI/TestSessionXML.cpp
@@ -1,4 +1,4 @@
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/Instrument/BackgroundItems.h"
 #include "GUI/Model/Instrument/InstrumentItems.h"
 #include "GUI/Model/Instrument/InstrumentModel.h"
diff --git a/Tests/Unit/GUI/Utils.h b/Tests/Unit/GUI/Utils.h
index d4dd7adddce140511445113254826e5f91f8bf88..49312f116bc0df736792ab9773c1fb586f8ca2ad 100644
--- a/Tests/Unit/GUI/Utils.h
+++ b/Tests/Unit/GUI/Utils.h
@@ -16,7 +16,7 @@
 #ifndef BORNAGAIN_TESTS_UNIT_GUI_UTILS_H
 #define BORNAGAIN_TESTS_UNIT_GUI_UTILS_H
 
-#include "GUI/Model/Group/PropertyItem.h"
+#include "GUI/Model/G6/PropertyItem.h"
 #include "GUI/Model/S3/SessionXML.h"
 #include "GUI/Util/XML.h"
 #include <QString>