I'm creating a survey for an electric system to collect the phase information. I want the possible downline phasing options to filter based upon the data collected. If Three Phase is chosen, the downline possibilities can be anything from the Phasing choice list. If Two Phase is chosen, the downline possibilities can only be Two or Single phase options that include that letter. If Single Phase is chosen, that phase is the only downline possibility.
Here is the Cascading Selects lists I have created:

Here are the Choice Filters I have tried:
(if${phasing2}='A'), (${phasenorth}='A')
(selected(${phase2}, phase)) or (selected(${phase2}, takeoff))
if${phase2}='Single', not(selected(${phase2}, takeoff))

Any suggestions would be greatly appreciated!