What does the cryptic crossword clue "Group from London area (close to Barnet) (3)" mean?

The definition is "Group". The wordplay uses a charade (building blocks). Hidden in "group from london area (cloSE To barnet)" The answer is SET.

Group from London area (close to Barnet) (3)

Times Cryptic #28803 | 7 Down | 2024-01-03 flower