AndreasR, Is it necessary left and right side to be different objects.
Now the problem is when colliding with left side it would pick that object but the right_platform is not specified so it picks them all.
If they have to be separate objects one way would be to but only left edge to the map and create container and but right edge there. Then on start it creates right edge automatically and you could set condition for the right edge like this.
On created -> Set position to left.Y and left.X+32(Tile width)
Otherwise you could use same events. Object picking works now when they are on same container.