The stage manager's little treasure (3)
I believe the answer is:
gem
'little treasure' is the definition.
(I've seen this in another clue)
'the stage manager's' is the wordplay.
'GEM' is hidden within the letters.
However, I'm unsure how this is indicated.
Can you help me to learn more?
(Other definitions for gem that I've seen before include "Setter might bed this" , "Treasured person" , "Pearl" , "Emerald or sapphire, say" , "A precious stone like a diamond or emerald etc" .)