You will need to be friends with each other over Xbox live before starting the game, if you friend whilst the game is open TuKraZe
notes that you will have to force close the game and restart it.
You can get this as either the host of a match or by joining, simply get in a party with a friend at the main menu. To create a party press
and use the Xbox's UI to invite the players you want and once at least one friend has joined look for an Online
Once the match begins the achievement is yours.Jobbenar
notes that the possibility for both parties to be on different server regions in game might hamper someone who isn't host from getting the achievement, so make sure you're on the same one.
If you need to boost this either create a gaming session
or use the gaming session panel to the right of this page to find one already created.