Compendium-TA has a hierarchy (or tree, or outline) based interface.

The Application Control Panel, provides a hierarchical approach to the management of the interface of the open models.

The main model browser, has a structural hierarchy of all the model information, and as many user defined and editable hierarchies as you need, to organize your information in the way that you want to.

Hierarchies can be viewed independently of the structural hierarchy in their own windows, and you can even view sub hierarchies in their own window to really focus in on the information that you want to work with.

And you can view graphs as hierarchies by using the NodeTree functionality.