Here's an example... I have a list with 3 columns: A, B, and C. None of the columns are unique but A and B together can only result in one C. I built a lookup to give me all of the A's. Then I attempt to build another lookup to give me all of the B's based on the A lookup control. It doesn't work, then I remember Nintex throws an ID in front of lookup values so I parse the value of A into a calculated column and use that for B's filter. Then I notice "The filtered by control must be a type that can post back" so a calculated value doesn't work either. Creating another list isn't an option so I'm stuck. Help is appreciated.