The same longing to be senior member (5)
I believe the answer is:
doyen
'be senior member' is the definition.
(I've seen this before)
'the same longing' is the wordplay.
'the same' becomes 'do' (abbreviation for ditto).
'longing' becomes 'yen' (yen is a kind of longing).
'do'+'yen'='DOYEN'
'to' acts as a link.
(Other definitions for doyen that I've seen before include "Most valued prof, eg" , "Member greatly respected" , "Group's senior member" , "Senior member of a profession or academy" , "The oldest of the members" .)