You need two outputs: go_to_ZONEA go_to_ZONEB {or something similar} Not sure what you're doing with your encoding?

Can I ask where this diagram came from? Did you make it with XCircuit or are there class notes posted somewhere?

You should mention that these are called transmission gates; building a transmission gate on a wafer makes sense because you have localized impurities/etc, but out of discrete components there might be an issue with matching - not sure, would have to check.