A small bureau's made up of experts (6)
I believe the answer is:
adepts
'experts' is the definition.
(adept is a kind of expert)
'a small bureau's made up' is the wordplay.
I cannot quite see how this works, but
'a' is present in the answer.
'small' could be 's' (abbreviation - e.g. clothes size) and 's' is located in the answer.
The remaining letters 'dept' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for adepts that I've seen before include "Very skilled persons" , "Expert or skilled people" , "Virtuosos, hotshots" , "People with talent" , "Pasted in by very skilful people" .)