Split up following business meeting to cut tenancy cost (8)
I believe the answer is:
fragment
'split up' is the definition.
(fragmenting is a kind of splitting up)
'following business meeting to cut tenancy cost' is the wordplay.
'following' becomes 'f' (used when citing page numbers etc).
'business meeting' becomes 'agm' (abbreviation for annual general meeting).
'to cut' is an insertion indicator.
'tenancy cost' becomes 'rent'.
'agm' going within 'rent' is 'ragment'.
'f'+'ragment'='FRAGMENT'
(Other definitions for fragment that I've seen before include "Small piece" , "Broken-off piece" , "Scrap" , "Piece broken off something else" , "Particle" .)