Hi Jonathan,
I create a simple example as follows:
Domain Model
Overview Page
Session New Edit Page
In the Host reference selector, I selected the following Constrained by
I then populated this with the following data:
And when I open the Session_NewEdit page, it doesn’t show any Hosts until a program is selected. Once a program is selected, it shows only the ProgramRepresentatives associated with the selected Program.
Let me know if you have any questions.
Mike