Detective taking in Split goes with the flow (6)
I believe the answer is:
drifts
'goes with the flow' is the definition.
I can't judge whether this definition defines the answer.
'detective taking in split' is the wordplay.
'detective' becomes 'ds' (detective sergeant).
'taking in' means one lot of letters goes inside another.
'split' becomes 'rift' (I've seen this before**).
'ds' enclosing 'rift' is 'DRIFTS'.
Can you help me to learn more?
(Other definitions for drifts that I've seen before include "piles!" , "Moves slowly, carried by a current of air or water" , "Heaps of snow blown by the wind" , "mine passages" , "Wanders around" .)