Concern where painter's daubed (7)
I believe the answer is:
pertain
'concern' is the definition.
('pertain' can be a synonym of 'concern')
'painter's daubed' is the wordplay.
'daubed' indicates an anagram (to daub is to spread something clumsily).
'painter' with letters rearranged gives 'PERTAIN'.
'where' is the link.
(Other definitions for pertain that I've seen before include "Painter (anag) - relate (to)" , "Relate (to), apply (to)" , "Painter inclined to be relevant" , "Refer" , "Be related or applicable (to something)" .)