To get this achievement, you must do a club vs club game via online matchmaking ONLY.
To do this, you must search any 2v2 standard or 3v3 standard in competitive (or casual) matchmaking, and you also need to be searching with one (in 2v2) or two (in 3v3) persons in your club in your searching group.
I recommend competitive because you're more likely to find grouped players and not bots, like you can in casual.
Randomly in matchmaking, you must find an opposition team that are in the same club (Edit: When I say the same club, I mean all of the opponents on the opposing team are in the same club, NOT in YOUR club.).
You'll know you've got that if the other team is not labelled as 'blue' or 'orange', but are labelled as whatever their team name is. You will also notice that the game's team colours (blue and orange) will be replaced by whatever your team colour's are, and whatever the opposing team's colours are.
When you're in a match, you need to score. The achievement will then pop.
Again, this can ONLY be done in club vs club. Having members of the opposing team that are in two different clubs will not work.