The most common and most likely answer to this crossword clue is the 7 letter word BRIEFER
I've seen this crossword clue in The Times
B
R
I
E
F
E
R
Buddy explains!

The straight part
We know that "One making presentation" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one making presentation = briefer.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 BRIEFER mean?
BRIEFER adjective- Of short duration; happening quickly.
- Concise; taking few words.
- Occupying a small distance, area or spatial extent; short.
- Rife; common; prevalent.
- One who provides a briefing.