diff --git a/file_handler.py b/file_handler.py
index 4c50dd3..61c317a 100644
--- a/file_handler.py
+++ b/file_handler.py
@@ -5,11 +5,12 @@ from enum import Enum
 
 class ItemDescriptor():
     
-    def __init__(self, name=None, id=None, type=None, value=None, definition=None, entity_type=None) -> None:
+    def __init__(self, name=None, id=None, type=None, value=None, definition=None, block_id=None, entity_type=None) -> None:
         super().__init__()
         self.name = name
         self.type = type
         self.id = id
+        self.block_id= block_id
         self.definition = definition
         self.value = value
         self.entity_type = entity_type
@@ -112,22 +113,23 @@ class FileHandler(metaclass=Singleton):
                 properties.extend(get_properties(fs))
         return sections, properties
 
-    def _entity_info(self, entities, entity_type):
+    def _entity_info(self, entities, block_id, entity_type):
         infos = []
         for e in entities:
-            itd = ItemDescriptor(e.name, e.id, e.type, definition=e.definition, entity_type=entity_type)
+            itd = ItemDescriptor(e.name, e.id, e.type, definition=e.definition, entity_type=entity_type, block_id=block_id)
             infos.append(itd)
+            # TODO set the value to something meaningful for the various entity types
         return infos
         
     def request_blocks(self):
-        return self._entity_info(self._nix_file.blocks, NodeType.Block)
+        return self._entity_info(self._nix_file.blocks, None, NodeType.Block)
         
     def request_data_arrays(self, block_id):
-        return self._entity_info(self._nix_file.blocks[block_id].data_arrays,NodeType.DataArray)
+        return self._entity_info(self._nix_file.blocks[block_id].data_arrays, block_id, NodeType.DataArray)
 
     def request_tags(self, block_id):
-        tags = self._entity_info(self._nix_file.blocks[block_id].tags, NodeType.Tag)
-        tags.extend(self._entity_info(self._nix_file.blocks[block_id].multi_tags, NodeType.MultiTag))
+        tags = self._entity_info(self._nix_file.blocks[block_id].tags, block_id, NodeType.Tag)
+        tags.extend(self._entity_info(self._nix_file.blocks[block_id].multi_tags, block_id, NodeType.MultiTag))
         return tags
     
     def request_references(self, block_id, tag_id, is_mtag):
@@ -137,7 +139,7 @@ class FileHandler(metaclass=Singleton):
             t = b.multi_tags[tag_id]
         else:
             t = b.tags[tag_id]
-        return self._entity_info(t.references, NodeType.DataArray)
+        return self._entity_info(t.references, block_id, NodeType.DataArray)
 
     def request_features(self, block_id, tag_id, is_mtag):
         b = self._nix_file.blocks[block_id]
@@ -148,7 +150,7 @@ class FileHandler(metaclass=Singleton):
             t = b.tags[tag_id]
         feats = []
         for f in t.features:
-            itd = ItemDescriptor(f.data.name, f.id, f.type, definition=f.data.definition, entity_type=NodeType.Feature)
+            itd = ItemDescriptor(f.data.name, f.id, f.link_type, definition=f.data.definition, block_id=block_id, entity_type=NodeType.Feature)
             feats.append(itd)
         return feats
     
@@ -157,5 +159,5 @@ class FileHandler(metaclass=Singleton):
         for i, d in enumerate(self._nix_file.blocks[block_id].data_arrays[array_id].dimensions):
             dim_name = "%i. dim: %s" % (i+1, d.label if hasattr(d, "label") else "")
             dim_type= "%s %s" % (d.dimension_type, "dimension")
-            dimensions.append(ItemDescriptor(dim_name, type=dim_type, entity_type=NodeType.Dimension))
-        return dimensions
\ No newline at end of file
+            dimensions.append(ItemDescriptor(dim_name, type=dim_type, entity_type=NodeType.Dimension, block_id=block_id))
+        return dimensions
diff --git a/tree_model.py b/tree_model.py
index 1d79da7..3162a8a 100644
--- a/tree_model.py
+++ b/tree_model.py
@@ -84,6 +84,15 @@ class BlockTreeItem(NixTreeItem):
             self._child_items.append(TagTreeItem(t, self._file_handler, parent=self))
         self._is_loaded = True
 
+class DataFrameTreeItem(NixTreeItem):
+    def __init__(self, node_descriptor, file_handler, parent=None):
+        super().__init__(node_descriptor, file_handler, parent=parent)
+        self._is_loaded = True
+
+class FeatureTreeItem(NixTreeItem):
+    def __init__(self, node_descriptor, file_handler, parent=None):
+        super().__init__(node_descriptor, file_handler, parent=parent)
+        self._is_loaded = True
 
 class DataArrayTreeItem(NixTreeItem):
     def __init__(self, node_descriptor, file_handler, parent=None):
@@ -91,7 +100,8 @@ class DataArrayTreeItem(NixTreeItem):
         self._is_loaded = False
     
     def load_children(self):
-        dimensions = self._file_handler.request_dimensions(self._parent_item._node_descriptor.id, self._node_descriptor.id)
+        self._child_items = []
+        dimensions = self._file_handler.request_dimensions(self._node_descriptor.block_id, self._node_descriptor.id)
         for d in dimensions:
             self._child_items.append(DimensionTreeItem(d, self._file_handler, parent=self))
         self._is_loaded = True
@@ -129,7 +139,14 @@ class TagTreeItem(NixTreeItem):
         self._is_loaded = False
 
     def load_children(self):
+        self._child_items = []
+        references = self._file_handler.request_references(self._node_descriptor.block_id, self._node_descriptor.id, self._node_descriptor.entity_type == NodeType.MultiTag)
+        for r in references:
+            self._child_items.append(DataArrayTreeItem(r, self._file_handler, self))
         
+        features = self._file_handler.request_features(self._node_descriptor.block_id, self._node_descriptor.id, self._node_descriptor.entity_type == NodeType.MultiTag)
+        for f in features:
+            self._child_items.append(FeatureTreeItem(f, self._file_handler, self))
         self._is_loaded = True
         
 class TreeModel(QAbstractItemModel):