Dignitary has fine, fine diamonds gold-plated (7)
I believe the answer is:
officer
'dignitary' is the definition.
(thesaurus)
'fine fine diamonds gold-plated' is the wordplay.
'fine' becomes 'f' (abbreviation).
'fine' becomes 'f' (abbreviation).
'diamonds' becomes 'ice' (I've seen this before).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'plated' means one lot of letters goes inside another (plated can mean covered or coated).
'f'+'f'+'ice'='ffice'
'ffice' going inside 'or' is 'OFFICER'.
'has' acts as a link.
(Other definitions for officer that I've seen before include "Possibly a major" , "eg Colonel" , "'An ... and a Gentleman, film (7)'" , "In the army, he's commissioned" , "Member of the armed forces in position of authority" .)