How do I make a floor mechanic?

Can anyone help me out:

To spawn a randomly different set of floors(floor of a building same width of the screen/layout) having a different number of people on each floor as the screen scrolls automatically upwards?

The floor must generate outside the layout before it is shown in the viewport.

I would really appreciate your help guys... specially if its a demo or example or file.

Check out this tutorial, maybe thats what you're looking for. construct.net/en/tutorials/procedural-dungeon-generation-708