I just gave this some thought last month. I did a thought experiment regarding this question.

What I saw was dimensions enclosed within dimensions as simply as a sheet of paper enclosed within all the air around it in the room with the air touching the paper at every surface, and the room enclosed within a building that surrounds every wall of the room, yet it was a cosmic space picture with familiar features of galaxies and black holes.

The boundaries between these dimensions were like a turbulent mirror which allowed most of the stuff in its dimension to be reflected back yet allow tiny parts to pass through. The dimensions were not like parallel branes but more like various yet similar fractal dimensions that differed only slightly as the scale in size varied from one to the next.

As black holes swallowed up bright matter and sent it hurtling into another dimension with the power of immense gravity, that other dimension (which touches every part of our dimension like the air around the sheet of paper) grew in mass equally to the amount of mass leaving our dimension. As the black holes became more numerous over time, more dark matter and energy resided in the other enclosing dimension which gave it more gravitational persuasion over our dimension and began to cause our dimension to accelerate toward every point in which it is surrounded by the dark energy mass dimension.

Instability built up over a near infinite period of time until the other dimension exploded back into the other nearly empty dimension through a weak spot as if the cosmic pendulum stopped and began to swing the other way.

This great cosmic breathe or undulating pulse of the universe was envisioned a bit like progeny being born while the prior version passed away. Like a Klien bottle, one dimension passes into another as inside and outside are same, yet within another Klien bottle.   The dynamic image of the thought experiment however was like a multiverse in which each bubble universe might sometimes burst making more but smaller bubbles on a smaller fractal scale dimension like foam on an infinite beach with countless bubbles of sizes that were clearly seen, all the way down to the microscopically invisible. Some of the bubbles were even able to combine and make a larger bubble from two or more bubbles.

Let me pause here and acknowledge the usual warnings against using human perceptions to make sense of other dimensions such as the quantum scale which can be viewed as a smaller dimension where things seemingly do not make "everyday" sense or obey laws that are familiar to our day to day life and bodies. It does begin to make sense when you envision a person looking at the quantum scale dimension yet seeing its alien time scale of eons pass in our nanosecond. This is why sub atomic particles sometimes seem as though they could be anywhere in a possibility cloud but only when we look are they seen to be in a particular position.

For me what I think was seen was a finite number of dimensions that dynamically influenced one another in an ebb and flow between themselves and that time was not a dimension in itself for everything there is, but was different and special for each dimension depending upon its mass and scale. It looked like interescting dimensional fractals intersecting each other according to their energies.

The less mass and the smaller dimension the more impossibly fast time would become. It seemed that the spooky action at a distance was a result of the turbulent mirror between dimensions where virtual particles pass to and fro. There was no explosive Big Bang in the dream image but instead it was rather like a mustard seed to to budding flower and shrinking back into entropy within all the dimensions at various time scales.

I have made a static graphic representation of these space time dimensions which looks a bit like a Klien bottle on steroids that I can post after dinner. A dynamic animation would of course be much better, but would take about a month to do and I have yet to clear all the storm damage we have had over the last 6 months.