View from one side supporting dossier (7)
I believe the answer is:
profile
'view from one side' is the definition.
(I've seen this before)
'supporting dossier' is the wordplay.
'supporting' becomes 'pro' (I've seen this in another clue).
'dossier' becomes 'file' (I've seen this in another clue).
'pro'+'file'='PROFILE'
(Other definitions for profile that I've seen before include "Sideways outline" , "Side view of face" , "In which one may be photographed" , "dossier" , "image" .)