The most common and most likely answer to this crossword clue is the 5 letter word RIFTS
I've seen this crossword clue in The Guardian
R
I
F
T
S
Buddy explains!

The straight part
We know that "splits" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case splits = rifts.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 RIFTS mean?
RIFTS noun- A chasm or fissure.
- A break in the clouds, fog, mist etc., which allows light through.
- A shallow place in a stream; a ford.
- To form a rift; to split open.
- To cleave; to rive; to split.
- (obsolete outside Scotland and northern Britain) To belch.