diff --git a/typetapper/hierarchy_graph_view.py b/typetapper/hierarchy_graph_view.py
index 8ea9480..304c2ed 100644
--- a/typetapper/hierarchy_graph_view.py
+++ b/typetapper/hierarchy_graph_view.py
@@ -135,6 +135,25 @@ class HierarchicalGraphWidget(QZoomableDraggableGraphicsView):
             self.current_group.am_event()
         elif isinstance(node, RelativeAtom):
             self.instance.workspace.jump_to(node.atom.loc.ins_addr)
+        elif isinstance(node, ExternNode):
+            atlas = self.ng.succ[node.adj_to]
+            rev = False
+            if self.current_group.am_obj not in atlas:
+                atlas = self.ng.pred[node.adj_to]
+                rev = True
+            if self.current_group.am_obj not in atlas:
+                l.error("?????")
+                return
+            attrs = next(iter(atlas[self.current_group.am_obj].values()))
+            further_edge = attrs['prev' if rev else 'next']
+            further_node = further_edge[0 if rev else 1]
+            if self.current_group.am_obj.parent == further_node:
+                target = ExternNode(self.current_group.am_obj)
+            else:
+                target = further_node
+            self.current_group.am_obj = self.current_group.parent
+            self.current_group.am_event(focus=target)
+
 
     def label(self, node: RelativeAtomOrGroup) -> str:
         if node not in self._labels:
@@ -563,15 +582,17 @@ class HierarchicalGraphWidget(QZoomableDraggableGraphicsView):
 
     # objectcontainer event handlers
 
-    def _on_change_group(self, **kwargs):
+    def _on_change_group(self, focus=None, **kwargs):
         old_group = self._old_group
         self._old_group = self.current_group.am_obj
         self._layouts[old_group] = {qnode.model: qnode.center for qnode in self.qnodes}
         self._layout(600)
         self._update_scene_rect(True)
-        if old_group in self.ug_reverse:
-            self.qnodes[self.ug_reverse[old_group]].setSelected(True)
-            self.centerOn(self.qnodes[self.ug_reverse[old_group]].center)
+        if focus is None:
+            focus = old_group
+        if focus in self.ug_reverse:
+            self.qnodes[self.ug_reverse[focus]].setSelected(True)
+            self.centerOn(self.qnodes[self.ug_reverse[focus]].center)
 
     def _on_selection_changed(self, src=None, **kwargs):
         if src == 'qt':