$settings = simplexml_load_file(__DIR__ . '/../../setting.xml');
Always keep in mine that
. (the CWD) is the directory of the PHP script at the root of any
require tree and only then if your configured
include_path actually includes
. (which it does by default though this can be changed in code).
home.php script is included by another script in a different directory,
. is relative to that other script.
__DIR__ makes sure you're always starting at the parent directory of the current script.