DRAGON BALL XENOVERSE 2

Since there wasn't a solution for this simple achievement, I figured I'd add one. All you really have to do is play through the story which will unlock most of the stages. You can also train with each instructor that is available, since there are stages you can get with them and they will help you acquire moves and xp to level up. I unlocked the achievement when I decided to finish off my remaining instructors and finished Lord slug, which has the stage for Tree of Might. A heads ups, you don't need all the stages to be unlocked for this achievement to pop, you just need to play on every map.

Get out there and kick some butt on the story and PQs.

Here are all the stages for an idea on what to look for and check off.
World Tournament
Hyperbolic Time Chamber
Wasteland
Mountains
Mountains Night
Pod Landing
Planet Namek
Destroyed Planet Namek
Tree of Might
Destroyed Cell Games Arena
Cell Games Arena
Archipelago
West City Suburbs
West City Industrial Sector
Capsule Corps
West City Ruins
Kami's Lookout
Sky
Beach
He'll
Supreme Kai's World
Underground Lake
Sky Earth
Sky Planet Vegeta
Glacier
Planet Tuffle
Open Field
Time Rift

Good Luck and have fun!