Here is the full list of all 5 Call of Duty: Black Ops II Multiplayer achievements.
Win 10 multiplayer games while playing in Party Games playlists.
Win 10 multiplayer games while playing in Combat Training playlists.
Reach Sergeant (Level 10) in multiplayer Public Match.
Prestige once in multiplayer Public Match.
Win 5 multiplayer League Play games after being placed in a division.