Multi-level master-details. How to?

Hi,

I'd like to have a page with DropDownList, GridView, FormView, and a list of
label/value pairs. The GridView records will be filtered out on the
selected value in the DropDownList. The FormView record will display fields
of the currently selected record in the GridView. I'm OK up to this point
because I've done it before.
Here is where I get lost. The record shown in the FormView (and selected in
the GridView) has associated records in the database. I'd like to display
them as a list so they can be inserted, updated, or deleted. Because these
records have only a single field (column) I'd like to display them on the
same page as the above mentioned controls.

Can someone please give me some ideas how to accomplish this?

Thanks,
Bogdan