UX/Design suggestions for non-hierarchy

I've got an interesting design challenge. My app has 3 topics in the top level of its information architecture (Why, Way and Do ). So it would be natural to split the functionality into 3 tabs or menu items. But I want people to be strongly aware of the other 2 topics while they are working with data in the 3rd topic as there is strong data linkages between the levels.

I'm looking for example patterns, where apps have done a good job of their information architecture, where the app is not purely hierarchical in nature but has cross-talk like this. Hope this is clear. If not, let me know and I'll try and give an example.

http://www.whywaydo.com