Jay I have some ideas in mind..
Let’s say you use it as a family tree.. Grand parents would be first header then Parents, then you, then children for the last level.
Then When looking at multiples families, you could filter in a list every people from the same “Generation”
(Maybe this particular scenario would not work, i’ve just made it up without really thinking about it!)
An other option I’ve started to imagine was having Clients as first header, then projects for that client in the next level. The other level might be sub-project or milestones. Then an other level for top level task list. Then from there you can use Projects, Bullet, Task and other item types for specific data entry!
I know that having more filters would make the filtering options a lot less intuitive so I think the best way to approach it would be to keep a “All Heading” filter in the suggestions and allow with the advanced search operators to search for heading:1, heading:2 etc for specific level filtering?
Again, I’m still in the free version but that’s a feature I think would be nice as a premium feature!