This is a slimeblock elevator powered by redstone. You select the floor level by using the arrow on an item frame and then just step into the elevator to go to the selected level. It’s really simple to build too. Have a look at the redstone and try to recreate it in one of your own worlds.
The elevator supports five different levels. You can of course add more levels to it if you intend to use it in one of your worlds.
To select a floor tap on the arrow in the item frame. In this case I decided to set it to #5. Then step into the elevator, stand on the slimeblocks and press the wooden button.
And as you can see, I was sent to the top floor (#5).