Action involving night flier may be discussed (7)
I believe the answer is:
'be discussed' is the definition.
(I've seen this before)
'action involving night flier' is the wordplay.
'action' becomes 'deed' (deed is a kind of action).
'involving' is an insertion indicator.
'night flier' becomes 'bat' (I've seen this before).
'deed' enclosing 'bat' is 'DEBATED'.
'may' is the link.
(Other definitions for debated that I've seen before include "Contemplated" , "Discussed formally" , "Considered" , "Discussed in public" , "Shared opinions" .)