I'm not entirely sure what you are asking here - I think you might have your terminology wrong.

It is possible to open multiple channels with one transaction, if that it what you mean, although not yet commonly done. It is also possible for more than 2 users to open a single channel by using something called Channel Factories, which allows more channels to be opened between all these users without requiring any further transactions to be broadcast to the base layer, but I don't know if this has actually been successfully done by anyone yet.