I’m not sure if you can do that.
Here is some general advice.
The only widget you can put other widgets into (as far as I know) is a “Container” widget.
So if you want to to put widgets into a particular widget, see if it is a descendent of PtContainer.
If not, I think you are SOL.
Thank you, I know the Container widgets. I thought: these widgets in the windows of PhAB, somehow a PtList/PtTree elements, and would be interested in how this can be done. I can choose a different path to solve the problem, thank you.