In this guide we’ll cover how to map an external domain to a WordPress Multisite subsite. This means a site created as subsite1.networkdomain.com, can be mapped to show as domain.com. This also works for subdirectory sites, so networkdomain.com/subsite1 can also appear at domain.com.
The first step is to add the domain as a Domain Alias in cPanel. This allows the domain to map to public_html, the directory where the WordPress site is installed.
Next you need to change the site URL within the Network Admin > Sites > Edit section.
Click Edit under the site you want to change…
Finally you’ll put in the new domain under Site Address (URL) and click Save Changes