A fine carnival's concerns (7)
I believe the answer is:
affairs
'concerns' is the definition.
(affair is a kind of concern)
'a fine carnival's' is the wordplay.
'a fine' becomes 'af' (I've seen this in other clues).
'carnival's' becomes 'fairs' ('fair' can be a synonym of 'carnival').
'af'+'fairs'='AFFAIRS'
(Other definitions for affairs that I've seen before include "Business; amours" , "Business and financial dealings" , "Current ones are of interest to the public" .)