Same level within department (3)
I believe the answer is:
par
'same level' is the definition.
(par is an average or standard level)
'within department' is the wordplay.
'within' says the answer is hidden in the clue.
'PAR' is hidden within 'department'.
(Other definitions for par that I've seen before include "Average score for good golf player" , "Usual score at golf" , "Rap to get even" , "Usual or expected level" , "Accepted level" .)