filtering one bound jList on anothers selected ID

I have two jLists bound to *different* tables using netbeans IDE persistence unit on a derby db

the second table (list) has a foreign key to the first tables ID (the foreign key is called groupID)

When the user clicks on the first list, I want to display only records in the second list that have the groupid of the first lists selected id. (err not a brilliant description but I how you understand!)

I'm struggling to progress further as I've not been able to find a similar tutorial.

Any ideas most welcome!
Thanks
Chris