Isometric game camera limits

I'm doing an isometric game, a view kind of like The Sims. right now I have an ortographic camera looking slightly downwards, and when I move it about x and y on it's local transform, the movement looks just how I want it, but it's actually moving in all three axes, world-position-wise, and I need to find a way to set the camera movement limits so it doesn't go off scene.

how can this be achieved?

Have the camera look at an invisible object with a collider and put "walls" around your world that won't let your invisible object (and thus the camera) leave the world.