I don’t think PHx can do this. I wanted to do something similar but PHx doesn’t have an elseif conditional. You could use nested PHx calls so that the first call checks one web group and displays one link. The else statement can call a chunk:
[+phx:mo=`webGroupA`:then=`<a href="[~id#1~]">link name</a>`:else=`{{nextGroupCheck}}`+]
In the {{nextGroupCheck}} chunk you can call PHx again to check the second web group and display two other links:
[+phx:mo=`webGroupB`:then=`<a href="[~id#2~]">link name</a>`:else=`<a href="[~id#3~]">link name</a>`+]
It might not the neatest way of doing it but it should work.