Fix function for parent that’s boringly complicated (9)
I believe the answer is:
rigmarole
'that's boringly complicated' is the definition.
'fix function for parent' is the wordplay.
I cannot really see how this works, but
'fix' could be 'rig' (rigging is a kind of fixing) and 'rig' is found in the answer.
'function' could be 'role' ('role' can be a synonym of 'function') and 'role' is found in the answer.
'parent' could be 'ma' (ma is a kind of parent) and 'ma' is present in the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
(Other definitions for rigmarole that I've seen before include "Lengthy and complicated procedure" , "boring series" , "A grim role for long rambling statement" , "Tedious procedure" , "Performance" .)