Passing information to forms

I am trying to use the knack GUI to build a set of forms. In the first form you select a Program (which has values such as name associated with it) Next, after you have selected this Program to view it, I have a set of people associated with the Program. Then I wish to create an interview for this Person. The Interview object has a Person and a Program connected to it. How do I get the Knack GUI to see these values for the selected Program and Person when creating an Interview via the menu?

I just started looking at Knack and am trying to do this without coding, just via the GUI.

Edit the form. On the second dropdown (People associated with the program) there should be an option called "Show" which lets you choose to show records that are associated with Program.