The UI for WinUI suite doesn't have a hierarchy-based control, but there is a feature request to introduce such. in the meantime, you can check the RowDetails feature of RadDataGrid and see if that would help.
Yeah that's a nice feature but still not what I was looking for. I found another way to present that will work but I will request that feature. You do have a TreeListView for WPF. You guys are good. Should take you about 4 hours to move that over. :-)