How to make an Actor visible only in a certain area of ​​the Viewport?

[KimCheolSoon]

I found the way in here :

Transparent material that hides any mesh behind it?

Hello everyone! I’d like to make a translucent material with “Disable Depth Test” ticked on for an optical illusion during gameplay. You wouldn’t be able to see it, but the player character gets hidden if they are behind it (sort of like an invisibility cloak). For example, if this material was on a sphere just floating in the middle of a room and then the player stops behind it, it’d look like the player model has a hole in their chest. Hope that makes sense! Thanks a lot in advance for the …

Material UI can’t use Custom Depth, So I make the occlude wall in front player’s camera and use it like widget.