Doing away with my initial question in the thread title, I think the best solution is to use DD the way it's designed with one exception - can I set up the parent-child list menu relationship based only on a single table in the database? Your solution may already address this, I will have to experiment a little.
Let's say the table contains 4 instances of ACME Corp in the company name field. They are distinguished by their locations, and we can treat city and state as a single entity. Originally I was thinking to use DD to simply display the corresponding location when the user selected one of the company name instances as it would show up in the parent list all four times. But that is clunky as they may have to make repeat selections.
So now, I plan on filtering the recordset on distinct company name (also greatly reducing the length of the list), and populating the child list menu with the four different locations. To do this the normal way, I would have to populate each record with a foreign key, then create a second table linking those keys to locations, correct?
So instead, could I just treat the company name as the identifier when creating the dynamic array? That would leave me with the four actual ACME Corp records, where I could combine the city and state to populate the child list labels, and the actual primary key ID as the value.