Help Please Backwards slider movement

How do i actually this slider attached with smth else as you can see go left? Trust me it goes the direction i don't want it to...i tried everything.

 

Never thought about how I could do. Because I was stuck on that part. I'll try out the 90° one, and change the attachments for the slider. Ill try out different directions also, and with smth like an example a wall next to wall it goes left, right? Because thats gonna be for one of my levels. Ill test the one with just the motor and I'll see if I can do smth with the other slider in one of my not fully created levels. Otherwise I have to change places of things In my level.

Thx!