Person seeking satisfaction from Mafia boss involved in robbery (8)
I believe the answer is:
hedonist
'person seeking satisfaction' is the definition.
'mafia boss involved in robbery' is the wordplay.
'mafia boss' becomes 'don' (I've seen this before).
'involved in' is an insertion indicator.
'robbery' becomes 'heist' (heist is a kind of robbery).
'don' going inside 'heist' is 'HEDONIST'.
'from' is the link.
(Other definitions for hedonist that I've seen before include "Self-indulgent type" , "he puts pleasure before work" , "For whom pleasure is the chief god" , "Seeker of sensual pleasure" , "A seeker after luxury" .)