Yes, you can customize and hide wp-admin path on Nginx server. Just follow the setup instruction.

Please read more details about How to configure Hide My WP Ghost for Nginx servers

Note! To change and hide the wp-admin path on Nginx Servers you need to have shell access to be able to reload the Nginx server.

UPDATE! Since Hide My WP Ghost 5.0, wp-admin can be hidden for Nginx servers.
It will require a config update after you update the settings in Hide My WP Ghost with the custom wp-admin path.

Read more details about how to configure Hide My WP Ghost for Nginx servers