There is some number of dimensions that exist in total, which is a number higher than just the four dimensions that we are readily able to observe. Our universe exists within this higher dimension, alongside other universes.

Also, what we perceive as linear time within our universe might not be just a single dimension either. But even if it's not we can still treat it as though it was.

The laws that apply within each of these four dimensional universes as we might see them might or might not all be the same laws. I.e. all other universes might have the same laws as does ours, or some might be different, or all might be different. We can't know.

But the idea that I like to entertain is that these universes could serve some function within the higher dimensions.

For example, a set of many many parallel universes might each function analogously within the higher dimensions as to how cells function in our universe, and that analogously these parallel universes form a greater whole together as some sort of being that is made up of all of these.

Or another possibility might be that a universe could be able to develop within itself life that is able to sense the higher dimensions, and to break free of the universe within which it was created and to then continue existing in the higher dimensions beyond the end of the universe that created it. I imagine this not as human with more senses, but something very different. For example, the way it might come into existence in our universe could be through machinery that we create, with mechanical sensors that are able to pick up the other dimension(s), and with increased computational power the machines we create could in turn process all of the information available to it in order to construct something that somehow (yes, very vague sorry) is not limited by the reality of our universe itself.

But yeah, there is no scientific basis for said ideas. It's just something that I like to imagine.