Feature of group given task (6)
I believe the answer is:
detail
This clue is a double definition.
'feature' is the first definition.
(I have seen 'Small feature ' mean 'detail' so perhaps 'feature' could also mean 'detail')
'group given task' is the second definition.
'of' acts as a link.
(Other definitions for detail that I've seen before include "Tailed into minutiae" , "A point or aspect of" , "Give full info about" , "Small fact or feature" , "Lead it (anag)" .)