Nest GridList possible?

[SpencerHC]

Hey all, I'd like to have a nested GridList, with drag and drop capabilities. Such as drag a child element to the parent GridList. Does anyone know if this is possible? Trying to nest GridList seems to throw an error, and attempting to do it in a hacky way with indented GridListItems seems to break the functionality entirely. Any ideas or insight?

I did find this discussion, but it doesn't really address to what I'm trying to do, which is primarily implement that drag and drop functionality. #7411