Unsolved QML TreeView display nodes by levels or custom delegate

[MikhailG]

Hello! I have a tree model derived from a QAbstractItemModel. And I can display the data in a tree like way (not threeway).
What I want is to display teh data by the layers. To display only one level of a layer at a time AND put each layer on a stack and navigate backwards by poping the layer from the stack.
I guess I have to implement a custom delegate? Any advice would be highly appreciated. Thank you.