How do I pinn only on one axis

a tricky question. this is what I would need: Imagine a verical thin square and a circle in the center of it. If I use arrows the circle can move only up down, the square only reft right. But I would like that the circle is somehow pinned on the vertical axis of the square...how would u do that ?

Simple for the square movement by make it moving in x-axis. For other, set circle.X same to square.X, then create individual controller for moving in y direction but don't forget to limit the movement.

thanks super helpful and kind:)