Influential film-maker's role (now less involved) (5,6)
I believe the answer is:
orson welles
'influential film-maker's' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'role now less involved' is the wordplay.
'involved' indicates anagramming the letters (involved can mean confusing or complex).
'role'+'now'+'less'='rolenowless'
'rolenowless' anagrammed gives 'ORSON WELLES'.
Can you help me to learn more?
(Other definitions for orson welles that I've seen before include "Director of the film Citizen Kane" , "Actor" , "Colossus of the performing arts" .)