To add a New Domain In your Multi Domain Hosting Plan
1: Login to your cpanel.
2: There under the section of " DOMAIN" you will find the option "ADDON DOMAINS", click on it.
3:Once you click there a new tab will open then under "CREATE AN ADDON DOMAIN", add your domain name at place of "New domain name" the "subdomain section" and "documentation root" will be filled automatically once you click on "ADD DOMAIN".
4:Once you click on the "ADD DOMAIN" addon domain will be added in your panel now you can host your website in your root folder of addon domain.
NOTE: Make sure you have updated the correct Nameservers for your New Domain.
To know your Nameserver open the link: https://www.globehost.com/nameservers/
Enter your Primary Domain Name for which you have purchased hosting from Globehost.
Update these Nameservers in your Domain Panel.
Within 24 hours of Nameservers update your site will start working. And you have to upload your files content to the Subfolder created with that Domain Name.