A problem with a shader to make a window transparent

Hi! I have some problems with a shader that I’m using to create the transparency of some windows (and doors) that the player can attach to walls. I’ve made a shader and it manages to create the transparency, but it doesn’t only omit the wall in which the piece in placed into, it also omits all the walls when seeing through the window. Any idea on how to apply the transparency only to the wall that the window is attached to and not all of them? Oh, and the window is a child of the wall once it is placed in-game, maybe that helps. Thanks in advance.