It does depend on the chameleon and truthfully, if you have enough space, you could probably make it work for any standard breed. However, if you do not have really small chameleons, it's almost certainly easier to separate them. They need to be able to get away from each other completely. I mean, they need to not see each other. That's far easier to achieve when they are in separate enclosures.
It's not a definitive thing. I've seen posts here about veiled and jackson's chameleons living in groups without problems for many years, so I know it can be done. But, in every case, there was a lot of space involved.