A switchboard operator? Most office workers have one (4,7)
I believe the answer is:
line manager
'a switchboard operator? most office workers' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'one' is the wordplay.
I cannot really understand how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'have' acts as a link.
Can you help me to learn more?
(Other definitions for line manager that I've seen before include "Person directly responsible for an employee" , "Immediate boss" , "fond of angling?" .)