Group shifting blame seen to lack answer (8)
I believe the answer is:
ensemble
'group' is the definition.
(ensemble is a kind of group)
'shifting blame seen to lack answer' is the wordplay.
'shifting' is an anagram indicator.
'to lack' is a deletion indicator.
'answer' becomes 'a' (abbreviation eg in Q and A).
'blame'+'seen'='blameseen'
'blameseen' with 'a' taken out is 'blmeseen'.
'blmeseen' anagrammed gives 'ENSEMBLE'.
(Other definitions for ensemble that I've seen before include "chamber group?" , "Group of musicians provide a full outfit" , "Musical company" , "team" , "Musical group" .)