This is a good question. And I don’t know the answer. Physicists are just getting started writing papers about the multiverse. I have been reading them some of them. First of all there is no spacetime in the multiverse. So how you would get from one spacetime continuum to the other is a very big question. Since we cannot get anything anywhere by any known means due to the speed of light in our universe, it is had to imagine how we would get from one spacetime continuum to another. We can imagine if it is impossible to go faster than the speed of light, then it would be even more impossible to move from one spacetime continuum to another. But since we are just starting to take the multiverse seriously I think it will be quite a while before we have any idea what it might actually be like in itself given the hints that we can get from the existence of our own universe.