As chief, he doesn’t succeed (6)
I believe the answer is:
leader
'as chief' is the definition.
'leader' can be an answer for 'chief' (I've seen this before). I'm not sure about the 'as' bit.
'he doesn't succeed' is the wordplay.
I cannot really understand how this works, but
'he' could be 'der' and 'der' is present in the answer.
The remaining letters 'lea' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for leader that I've seen before include "One in command" , "One is ahead and shows the way" , "Boss, commander" , "Party head" , "Head of an orchestra" .)