adding the ..\addresses the next folder above the current level.
So, ..\%_parent_directory%
would address the folder above the parent directory and ..\..\%_parent_directory%
would address the folder above the folder that is above the parent directory.
And as this may be getting rather confusing, I would suggest to use an absolute path.
Of course not as it is a relative path.
Perhaps you have to use a function to count the slashes or backslashes to get the right part. If you have to count from the end, perhaps the function $reverse() helps.