require_some => {
    # require any two fields from this group
    city_or_state_or_zipcode => [ 2, qw/city state zipcode/ ], 
 }
So I tried doing:
 require_some => {
    # require any two fields from this group
    american_phone => [ 2, qw/p1 p2 p3/ ], #the input field names are p1 p2 p3, american_phone is the constraint name.
 }