Group taking a bit to produce special item (3,5)
I believe the answer is:
set piece
'special item' is the definition.
(special item or part of something)
'group taking a bit' is the wordplay.
'group' becomes 'set' (both can mean a collection).
'taking' is a charade indicator (letters next to each other).
'a bit' becomes 'piece' (a bit is a small piece).
'set'+'piece'='SET-PIECE'
'to produce' acts as a link.
(Other definitions for set piece that I've seen before include "Carefully planned manoeuvre" , "Something arranged for maximum effect" , "Formal or elaborate arrangement as in art" , "firework display" , "Carefully structured and practised speech - see pi, etc (anag)" .)