Looking at the clause
"... to talk to two separate people or groups involved in a disagreement"
is the word 'involved' an adjective here? If it is, shouldn't it be 'that are involved'?
Looking at the clause
"... to talk to two separate people or groups involved in a disagreement"
is the word 'involved' an adjective here? If it is, shouldn't it be 'that are involved'?