At one stage in an effort to understand the various components I attempted to "map" a Revit Project with MindManager. You can see the result of that below but it's far from complete (with no MEP or Structure) and has one major limitation. MindManager can show hierarchy but doesn't really have a mechanism to show the complex inter-relationships between Revit database elements. It does have a relationship arrow, and topics can have multiple relationships, but attempting to show all the connections would result in a mass of arrows.
Last year Rich Sales presented his view of the Revit Project to RUGAKL using another mapping product; PersonalBrain. It's advantage is an ability to handle multiple relationships between topics and present them in a dynamic responsive view. As you click on topics the Brain adjusts to show the relationships with notes or images zooming out when you hover over the topic icons (like I wish MindManager did!).
Rich has put his Revit Brain on-line and you can give it a spin here: http://webbrain.com/u/103E