Scope or extent of limited ambition (5)
I believe the answer is:
ambit
This clue might be a double definition.
'scope' is the first definition.
(synonyms)
'extent of limited ambition' is the second definition.
'ambit' can be an answer for 'extent' (ambit is a kind of extent). I am not certain of the 'of limited ambition' bit.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for ambit that I've seen before include "Circuit, compass" , "Circumference" , "Compass, scope" , "Scope, extent, or bounds of something" , "Range - surroundings" .)