This achievement requires you to complete a match on each of the twenty-one multiplayer maps [accessible through the 'Xbox Live' menu entry].
Six maps are playable only through Siege mode, but all can be played through matchmaking or custom games.
By creating a "custom match with party" you can play by yourself and alter game settings. This allows you to flow through these much more quickly.
.________mode: Anarchy ._round time: one minute
Crash Site
Deadzone
Downfall
Excavation
Fall Factor
Garrison
Pinnacle
Quarantine
Radial
Rift
Sand Pit
Settlement
Warlords
Wasteland
Wreckage
.________mode: Siege ._round time: one minute [per team]
Cornered
Crescent
Crevice
Framework
Gauntlet
Overpass
[note: you can also rotate through a match on each of the other playlists to snag another achievement.]