hi…i need a help how to make it work…
you can’t do it using the collider info which isnt sent to the shader, if you have a sphere with a mehs collider it perhaps can be done using transparency settings, i dont see how though. to make a transparent round area you can do a loop of 1-10 moving circles around cubes if you want, which will set alpha of plane at zero near any of 10 vector3 that are sent to the shader.
thanks @drudiverse , waiting for another 
if the plane is always flat you can maybe use a circle mesh that follows the box, and there may be an option in shader blending (See blend page) that can make both transparent if one is on other. if you can manage that then the circle option is the best.
the plane is always flat, may you can send me an link to help me
Okay sorry i didnt check my msgs, was working on other things.
there are 2 of these vids
You need to look at shader blend mode page
your question is actually this:
How do i make parts of a mesh invisible when they are seen through another mesh.
… basically, if you have a round cirle with alpha zero, you can make the background object invisible with one of the blend modes, like 1-source alpha i dont know the details.
i know i would use the method with a loop that makes alpha = zero if distance to list of points smaller than radius. its abit complex but at least i know how to do it and, your flat thing should manage 100+ invisible round bits in a loop on pc easy, dunno about mobile, at least 10-30 id think.
blend version maybe ask a new question to get details.
actually im build an moba game, like LoL, i know little about unity networking, and photon networking solution.
in this case, ill be using it to FogOfWar/DarkMap.
thanks @drudiverse i found video www.youtube.com/watch?v=yzcfTb9e0lo, and im trying to make it as own solution.
but im not sure if this video are best solution