The most common and most likely answer to this crossword clue is the 10 letter word MANOEUVRES
I've seen this crossword clue in The Guardian
M
A
N
O
E
U
V
R
E
S
Buddy explains!

The straight part
We know that "Moves across battlefield" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case moves across battlefield = manoeuvres.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 MANOEUVRES mean?
MANOEUVRES noun- The planned movement of troops, vehicles etc.; a strategic repositioning; (later also) a large training field-exercise of fighting units.
- Any strategic or cunning action; a stratagem.
- A movement of the body, or with an implement, instrument etc., especially one performed with skill or dexterity.
- A specific medical or surgical movement, often eponymous, done with the doctor's hands or surgical instruments.
- A controlled (especially skilful) movement taken while steering a vehicle.
- To move (something, or oneself) carefully, and often with difficulty, into a certain position.
- To guide, steer, manage purposefully
- To intrigue, manipulate, plot, scheme