Hi Jeff,
Can you use a dataview as a listener for list 2, and use a datagrid with datasource over association or reference set selector to display list 2?
Here’s an example I set up.
Domain Model
Page
The category list is on the left with data source from database. The items list is in a dataview listening to the category list, and is using a datagrid over an association. Then the accessory list is in a dataview listening to the items list, and using a datagrid over association.