Chartered accountant, for example, participating in Conservative group (8)
I believe the answer is:
category
'group' is the definition.
(both can mean a class or type)
'chartered accountant for example participating in conservative' is the wordplay.
'chartered accountant' becomes 'ca' (abbreviation for chartered accountant).
'for example' becomes 'e.g.' (synonyms).
'participating in' indicates putting letters inside.
'conservative' becomes 'tory' (informal term for a Conservative Party member).
'eg' going inside 'tory' is 'tegory'.
'ca'+'tegory'='CATEGORY'
(Other definitions for category that I've seen before include "Type" , "Class or order" , "Logical grouping" , "Group of classified items" , "Class or division of similar subjects" .)