The best from Brussels, maybe (4)
I believe the answer is:
tops
'the best' is the definition.
(I've seen this before)
'from brussels maybe' is the wordplay.
I cannot really understand how this works, but
'from' could be 'o' (I've seen this in other clues) and 'o' is found within the answer.
The remaining letters 'tps' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tops that I've seen before include "Maybe puts icing on" , "Excellent" , "The best" , "The Four -, Motown group" , "Upper garments" .)