This dream seemed to be inspired by the TV show Snowpiercer.
All that I can remember of this dream is that a lot of the world seemed to be living in one or more large (giant) apartment buildings, I could be wrong though, and most of the dream took place inside a large multi-story apartment building.
This apartment was divided / segregated by social class / income / et cetera with the rich / upper class / high income / 1st class being on the upper floor(s), the middle class / 2nd class being on the middle floor(s), the lower class / low income / 3rd class being on the lower floors except for the ground floor, and the ground floor was where they processed people wanting to live in or visit the apartment.
Most of the dream seemed to take place in the 2nd class section, which was pretty nice-looking like on the TV show Snowpiercer, I was mostly following some of the people who lived in 2nd class, and they lived a pretty luxurious life with most of the things that they wanted.
If 2nd class was that nice, I wonder how amazing 1st class was, but I never got to see 1st class during the dream because you could probably only visit lower than your class if you had permission / could get through the checkpoints.
At some point the group of people from 2nd class I was following were smuggling very large fish from 3rd class into 2nd class, I think they wanted them as pets in their aquariums, and this group of people were also part of some secret resistance group who were working with people from 3rd class hoping to end the segregation by class.
They hacked at least one of the elevators to take them wherever they wanted, and they used this hacked elevator often to get past security / restrictions / et cetera.
At some point when I was walking around probably following the others, I overheard maybe a British man with light-color skin with short blond hair wearing glasses from maybe 1st class talking with a high-level security person / administrator, he was talking about a British themed area.
At some point I used the elevator, and I somehow accidentally got taken to a secret hidden floor that was still under construction; it was dimly lit with red lights.
I saw a man who looked like or was Yahya Abdul-Mateen II, he was part of the construction crew, he told me that I was not supposed to be there; and I tried to talk him out of reporting me to security, I possibly told him about the resistance group, but I can not remember.
It looked like they were secretly building a British themed floor or area, and I wondered if they were going to replace or downgrade one of the classes.
Yahya Abdul-Mateen II was afraid and he said that it was all top secret and that he could not tell me, and he probably let me go without reporting me.
I then took the elevator to the ground floor that was also dimly lit, there were many people down there waiting to be processed, some were hoping to live in the apartment, and some were there to visit like maybe my mom or someone else’s mom.
The dream then jumped to somewhere outside the building, maybe an island or some other land, and the people there had light-medium color skin.
Several women were talking to their mom complaining about how their brother had abandoned them and their island / land / country / people to go live inside the apartment, they were a proud people, and they mentioned something about the toxic levels rising and maybe their land / island was dying and / or becoming uninhabitable; but they did not want to abandon it yet.
But that is all that I can remember of this dream.