Open about amount of work experience (7)
I believe the answer is:
'experience' is the definition.
'open about amount of work' is the wordplay.
'open' becomes 'undo' (eg opening a bottle).
'about' is an insertion indicator.
'amount of work' becomes 'erg' (scientific unit for work or energy).
'undo' enclosing 'erg' is 'UNDERGO'.
(Other definitions for undergo that I've seen before include "Submit to an experience" , "Suffer, endure" , "Endure for guerdon" , "Withstand" , "Endure - urged on (anag)" .)