The most common and most likely answer to this crossword clue is the 3 plus 1 plus 4 letter word ACT A PART
I've seen this crossword clue in The Daily Telegraph
A
C
T
A
P
A
R
T
Buddy explains!
The straight part
We know that "Play a role in drama group" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case play a role in drama group = act a part.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.