For big business leaders, change management's losing men (8)
I believe the answer is:
magnates
'for big business leaders' is the definition.
'change management's losing men' is the wordplay.
'change' indicates anagramming the letters.
'losing' is a deletion indicator.
'managements' with 'men' taken out is 'managets'.
'managets' anagrammed gives 'MAGNATES'.
(Other definitions for magnates that I've seen before include "Business tycoons or influential people" , "Very wealthy or powerful businessmen" .)