One suggesting taking problem to specialist (8)
I believe the answer is:
proposer
'one suggesting' is the definition.
'problem to specialist' is the wordplay.
'problem' becomes 'poser' (poser is a kind of problem).
'to' says to put letters next to each other (I've seen this in other clues).
'specialist' becomes 'pro'.
'poser' after 'pro' is 'PROPOSER'.
'taking' acts as a link.
(Other definitions for proposer that I've seen before include "One making toast" , "One putting forward idea" , "One makes a formal motion" , "One coming up with" , "Advocate" .)