Determine a site by its domain and path.
This allows one to short-circuit the default logic, perhaps by replacing it with a routine that is more optimal for your setup.
Return null to avoid the short-circuit. Return false if no site can be found at the requested domain and path. Otherwise, return a site object.
(null|false|WP_Site) Site value to return by path. Default null to continue retrieving the site.
(string) The requested domain.
(string) The requested path, in full.
(int|null) The suggested number of paths to consult. Default null, meaning the entire path was to be consulted.
(string) The paths to search for, based on $path and $segments.