This is not a canonical fight, and is instead a strange, but awesome mishmash of Star Wars eras. Darth Maul eventually reveals himself as a threat, as does Boba Fett, and then Rey and Han Solo show up to defeat them. If you're trying to work out when this battle takes place in the Star Wars timeline, don't. We are instead treated to a new conflict that sees the Separatists' robotic forces clashing against the Republic's clone army.
This is not their fight, and it isn't a battle George Lucas dreamed up for The Phantom Menace. Don't expect to see gungans saving the day through accidental actions, or even the queen's forces setting up a blockade outside of the throne room. The map is called Assault on Theed, and is set in the heart of the capital city of Naboo, which is also home to Queen Amidala. Rather than piggybacking off of the recent success shared by the films Star Wars: The Force Awakens and Rogue One: A Star Wars Story, Battlefront II's first multiplayer map takes gamers to the prequel era, and more specifically to where the gungans roam. Star Wars Battlefront II's multiplayer didn't debut on a planet Poe Dameron frequents, or a place Jyn Erso calls home.