Clip Mask, Show only what's inside the sphere

Generally I ask, how to achieve this effect → All Objects inside the sphere are visible, otherwise they cut or hidden.

Stencil was a good start, but when I look through the Sphere, I see other Objects, which I don’t want to achieve.

Hope someone can put me in the right direction.

Does it work, when I have more than one “Vision-Sphere”? Cheers