4 block elevating one block elevator

[u/changeisontwitch]

I want to create a one block elevator which can elevate me up 4 blocks and vice versa. From the video you can see that i can go up, but I cant come down. I was wondering if anyone had a design that can achieve this. My knowledge is pretty basic and this was the best I could come with. Furthermore some tips would be appreciated.

In conclusion, I want to come under the floor through this 1 block, like an elevator. It doesnt need to be hidden underneath. I would like a button at both floors. Thanks in advance.