How do I switch these levers into an on and off button?

Purple – input block
Green – (hypothetical buttons)

I wanted to use buttons instead of levers since the variations blend in well with the blocks, but it's been difficult on my end. For context, I'm building a hidden staircase. I tried it with pistons and a redstone block, but you can only close/open it on the other side. I'm playing in a multiplayer world, and I wanted to close it while I'm below.

The 2nd image seems to be the only thing that's working, but I just have no idea how to add another button on the other side. Any suggestions? (I'm a visual learner, so it would really help if there are images that can help me…)