Back to original question, if I may? 
My want is to have a single hierarchical view, in DT, of all files (Markdown, PDF, etc) stored in DT (whether directly or indexed from Obsidian). The hierarchy of this view is based on Company/Client/App/Function.
i.e.;
All files related to Client A - including all its Apps and Functions
All files related to Client B’s HelloWorld app - and its functions
All files related to Client C’s ThisIsMe app’s data processing function
I was trying to acheive this by using tags, tag groups, etc
Is the above possible?
