How do you make a transform dissappear from game view on command and reappear when needed?

Like how can I make something leave then comeback?

Transforms aren't visible in the first place. You could make your meshes not be drawn by using Renderer.enable, you can make your objects non-active by using GameObject.active, or you can destroy an object and then re-instantiate a prefab in its place. It depends on why you want it to disappear, and under what conditions it should reappear...