The most common and most likely answer to this crossword clue is the 4 letter word EXEC
I've seen this crossword clue in The Times
E
X
E
C
More clues leading to the result EXEC
- Retiring Church Times editor's first boss
- Former city business manager
- Bosses no longer linked to one part of the establishment
- Manager in old country club, once
- Business manager and former partner, each appearing on and off
- Chief Justice Knox became empathetic at last
- Former City boss?
- Director having sex, second pair of smalls discarded
- Senior official‘s vote in chamber’s first up
- River Clyde’s first business leader
Buddy explains!

The straight part
We know that "business manager" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case business manager = exec.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.
What does EXEC mean?
EXEC noun- Executive, executive officer
- To execute; to run.