The most common and most likely answer to this crossword clue is the 6 letter word SNACKS
I've seen this crossword clue in Financial Times
S
N
A
C
K
S
Buddy explains!

The straight part
We know that "nibbles" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nibbles = snacks.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 SNACKS mean?
SNACKS noun- A light meal.
- An item of food eaten between meals.
- A very sexy and attractive person.
- To eat a light meal.
- To eat between meals.
- A share; a part or portion.
- To snatch.
- To bite.
- To share.