Distinguished group with a role to play (3,5)
I believe the answer is:
set apart
'distinguished' is the definition.
(I've seen this in another clue)
'group with a role to play' is the wordplay.
'group' becomes 'set' (both can mean a collection).
'with' says to put letters next to each other.
'role to play' becomes 'part' (I've seen this in another clue).
'set'+'a'+'part'='SET APART'
(Other definitions for set apart that I've seen before include "Distinguished" , "Isolated" , "singled out" , "reserved" , "Keep separate (for a special purpose)" .)