Level-headed business manager initially worked as model (8)
I believe the answer is:
composed
'level-headed' is the definition.
(thesaurus)
'business manager initially worked as model' is the wordplay.
I cannot quite understand how this works, but
'business' could be 'co' (short for company) and 'co' is present in the answer.
'model' could be 'pose' (model can mean to pose) and 'pose' is located in 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 composed that I've seen before include "Made a score" , "with aplomb" , "Still - contrived" , "Settled" , "Wrote music" .)