The most common and most likely answer to this crossword clue is the 3 plus 2 plus 1 plus 3 letter word GET IN A RUT
I've seen this crossword clue in The Daily Telegraph
G
E
T
I
N
A
R
U
T
Buddy explains!
The straight part
We know that "Find oneself in the groove" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case find oneself in the groove = get in a rut.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.