Datatables as editor field

This is probably pretty trivial, but I can't seem to figure this out.
I have a list of parts being displayed in a datatable. Each of those parts can have sub-parts associated with each of them. When the user selects one of the parts I would like the editor to list, in a datatable, the sub-parts associated with that part that they selected. Once the editor is open, they can add/edit/delete from that list of sub-parts.
Do I need to fill the datatable of sub-parts on the editor preOpen event?
Looking for the best solution.