Supervisor, manager (8)
I believe the answer is:
director
This clue is a double definition.
'supervisor' is the first definition.
(director is a kind of supervisor)
'manager' is the second definition.
(synonyms)
(Other definitions for director that I've seen before include "Senior person in a firm, executive or non-executive" , "One on board" , "Big cheese" , "Business manager or film maker" , "Record it (anag.)" .)