Files outside of WordPress directory

Hi I’m trying to use a path outside of the default root.

default root: /var/www/site/ and I can only give paths within this folder to the path parameter.

I’ve changed def. root to: /var/www/ (makes no difference)

my folder is at: /var/www/mainfolder/subfolder/

tried these combinations:
path”mainfolder/subfolder”
path”var/www/mainfolder/subfolder”
path”/var/www/mainfolder/subfolder”
path_type=”outside” url”var/www/mainfolder/subfolder”
path_type=”outside” url”mainfolder/subfolder”
path_type=”outside” url”/var/www/mainfolder/subfolder”

nothing works.