Resolve reportedly more brilliant positions son's advanced (8)
I believe the answer is:
finalise
'resolve reportedly more brilliant positions' is the definition.
I know nothing about this answer so I can't tell whether this works.
'son's advanced' is the wordplay.
I cannot quite see how this works, but
'son's' could be 's' and 's' is present in the answer.
'advanced' could be 'a' (abbreviation) and 'a' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for finalise that I've seen before include "Agree on definitive version of something" , "settle" , "Conclude" , "Put an end to, complete" , "Put the last touches to" .)