I have a bathtub with a mounted lever for the drain.
Occasionally if someone accidentally moves the lever a little bit, it leaks from somewhere behind the tub. It drains through the floor into my basement. I have to fiddle with the lever (it sometimes is hard to stay in the position) .
I am not sure if there is a way to fix it or would I just have to replace the whole thing?

There should be a access panel behind the drain. Open it up and tell me exactly where the leak is. Good luck, Tom