Choose group appearing in top twenty
I believe the answer is:
opt
'choose group' is the definition.
'opt' can be an answer for 'choose' (both can mean to pick something). I am unsure of the 'group' bit.
'in top twenty' is the wordplay.
'in' says the answer is hidden in the clue.
'OPT' is hidden in the letters of 'top twenty'.
'appearing' is the link.
Can you help me to learn more?
(Other definitions for opt that I've seen before include "Prefer, choose" , "Plump for" , "Have preference for something" , "Select as a preferable alternative" , "Decide between possibilities, choose" .)