Complex multilevel app design

I’d like to have an app structure which allows individual elements to belong to multiple trees at different levels vs. only a single tree without duplicating data and allowing tree levels additions to be included on the fly.

I made an attempt along the lines of the Category-Subcategory tutorial at … with the intent of having two or more inline lists available (in this case, one for Anatomy and one for physiology) based on two Parent and two Children lists.

However, it appears I can only draw from one child list at a time vs being able to use Children1 for the Anatomy tab and Children2 for the Physiology tab.

I know I can setup multiple multiple relations vs category/subcategory … but the ability to maintain a complextree structure in certain situations is advantageous.

Any ideas appreciated … Thanks very much!

Filed in Showcase Apps but also filing in bugs in csse the inability to assign two different Child Lists to two different tabs is in fact a bug.