How do you handle multiple floors?

I am working on starting up an urban fantasy game.  There will be lots of buildings to climb up the out side of, balconies to jump off of, and roofs to slide down. This will involve a lot of changing of levels, which are usually stored on other map pages.  Also, my players feel no shame in splitting the party so the GM has to keep hopping from map to map through out combat. So, when doing such a campaign, how does those who run the game utilize Roll20 to handle such events?  Are all of you "floors" on one map separated by dynamic lighting?  Do you have the floors stacked on top of each other (on the map layer) and keep pushing the map 'to the back' when changing levels?  Or is there some other kind of Roll20 magic I am unaware of?

In addition to the separating using dynamic lighting, you could make the map a large  rollable token . It functions the same as the "to the back" method, and is more work up front, but it saves you so much time in game.

I like the rollable token idea. The problem I run into is simultaneous action on multiple floors as well as the stairwell between them. I usually solve that by having both maps on the same page and ping-pull to whomever's turn it is.

I generally store multiple floors on one page, after I stitch them together in gimp.

I have often done multiple levels on one Page, and even make long pathway lines or hallways (these can be dynamic lighting tunnels with walls) which simulate the path of stairwells. This gets tricky and the stairwells are NOT realistic in size, length, direction. They are like tunnels outside the maps that lead from where one stair or doorway departs, and arrives at where the stairway terminates entering the other floor. Think sort-of like the game chutes-and-ladders, these are connection-hallways outside the borders of the floorplan-maps, that draws a path from the edge of 2nd Floor to the entry of 3rd Floor, so that tokens can actually walk/move that way themselves.

I've used multiple floors on the same page, and then used the Teleport script to move tokens from one floor to the other automatically.  This works best with smaller maps though, and lately I've gone back to having multiple floors on multiple pages.  There's a script for moving tokens automatically from one page to the other as well, but I've not used it, so can't comment on how well it works.