Past one's peak in more ways than one (4,3,4)
I believe the answer is:
over the hill
'past one's peak' is the definition.
I know nothing about this answer so I can't tell whether this works.
'more ways than one' is the wordplay.
I cannot quite understand how this works, but
'more' could be 'over' (I've seen this before) and 'over' is located in the answer.
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
This may be the basis of clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for over the hill that I've seen before include "generally declining" , "Getting on" , "Obscured by the scenery" , "Into the next valley" , "walk up and down here?" .)