Understand clubs, for example, do the same thing (6,4)
I believe the answer is:
follow suit
'do the same thing' is the definition.
'understand clubs for example' is the wordplay.
'understand' becomes 'follow'.
'clubs for example' becomes 'suit' (clubs is a playing card suit).
'follow'+'suit'='FOLLOW SUIT'
(Other definitions for follow suit that I've seen before include "Play another club, perhaps" , "Do as others do" , "Be guided by corporation man" , "Do the same as someone else" , "go from club to club" .)