You can assign multiple domains to your Website Builder Website. The domains display the same Website as the primary domain associated to the Website Builder account.
Assigning multiple domains to a single Website Builder Website is called domain aliasing. Aliasing is preferred to forwarding domains to your Website as forwarded domains are less searchable than an aliased domain.
You can only alias domains that are available within your customer account. Please allow up to 48 hours for the aliased domain to display your Website.