as title, of course, we can get it with multiple level QSortFilterProxyModels, but single one is better. (indeed, I encountered crash when change model with different columnCount)

another one, in TreeView, we can't assign rootIndex simply but with multiple level call of 
mapFromSource on original model.

with multiple filter condition, we can do more complex filter on one model.

how to implement it with new interface or property should be reconsidered.

one filter condition should contain role, column or row index (or range), regex and so on.

maybe the property used for filter should be a list of it.

just like it:
https://github.com/RaymiiOrg/SortFilterProxyModel