Recent SwitchBuddy update added new option how to filter games. This can be used with Deals or when browsing games in particular genre and also when browsing either Split-screen or Co-operative games.
It is actually very simple! The new filter is named “Players” and you can find it in the first section. Just tap the “+” button to specify minimum player count on single Switch. This is easpecially useful if you are looking for games that support four or even eight players.
To make this even better, also specify the “Minimum average rating” value to get the best games. I usually select 70 for this slider to make sure there’s enough games to check out. Not every good game is 90+ and even games with lower score can be awesome fun when played with friends together.