Here is a simple way to enable directory listing in Nginx Webserver.
I have a subdomain repository.wowtutorial.org and i want repository.wowtutorial.org to have ability to listing a directory.

All we need to do just modify the vhosts or nginx.conf
Add autoindex on;

Please see the example below

Example :

#pico /usr/local/etc/nginx/vhosts/repository.wowtutorial.org

server {
        listen  80;
        server_name  repository.wowtutorial.org;
        autoindex on;

        location / {
            root   /home/xxx/repository;
            index  index.php index.html index.htm;
        }

        location ~ \.php$ {
                fastcgi_pass   127.0.0.1:9000;
                fastcgi_param  SCRIPT_FILENAME  /home/xxx/repository$fastcgi_script_name;
                fastcgi_param PATH_INFO $fastcgi_script_name;
                include        /usr/local/etc/nginx/fastcgi_params;
        }


        location ~ /\.ht {
            deny  all;
        }
}