You'll probably get this on the way to Triple Five Wins if you have a four-person boosting group.
You just have to win 5 ranked matches in any ranked multiplayer mode, including 2-player vs., 4-player vs. or 4-player team vs. If you only have one other person to boost with, you'll obviously have to do this in 2-player vs. This will go very quickly when boosted and everyone just drops pieces until they lose.
You can check your stats in the leaderboards if you are not sure how many wins you have for a particular mode. It's unclear if the wins can be spread across multiple game types or if it has to be five wins in a single game type.