There is a tool you can use to play WaW and B02 in Split Screen up to 4 players. Just don't use it on plutonium, because I'll trigger the anti-cheat and you will be banned. If you really want to play in Split Screen, then lookup the tool called Nucleus Co-op and buy the game. I've tested both games already with the tool and it's fun when someone comes over to play.
Reminder don't use the tool with plutonium