3 Mutually exclusive groups: how to declare required parameters?

[ZedZipDev]

I have 3 SetName mutually exclusive groups. In every group I'd like to have required parameters. 1 p11 (required=true) p12 (required=false) 2 p21 (required=true) p22 (required=false) 3 p31 (required=true) p32 (required=false)

By fact: the application detected group 2 it generated error that no required parameter p11. But it is from group 1. I do not need it. When I have declared all options Required=false it helped.

What I do wrong?