nginx code to setup magento 2 multi store

location /sub_directory {
        root $MAGE_ROOT;
        location ~ ^/sub_directory/index.php {
        fastcgi_pass   fastcgi_backend;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;
}
}