Multiple Subdomain Tracking?

I’m having some trouble figuring out how to use the Advanced -> Subdomain Tracking setting for multiple subdomains.

The tooltip is very unclear and the plugin documentation is also confusing.

Should I just enter all my subdomains in that field, separated by a comma? Do I need to include http:// in the domains entered in here?

https://wordpress.org/plugins/google-analytics-for-wordpress/