This page explains how to set redirection to mapped domains, so users can only see the mapped version of a page when using Domain Mapping System.
When the setting Force site visitors to see only mapped domains of a page is enabled, anytime visitors attempt to navigate to a page that is mapped, they will by default be redirected to the first mapped domain associated with that page.
This prevents site visitors from ending up on an unexpected domain than the one they were previously navigating.
If this feature is used simultaneously with Global Domain Mapping, all pages on your site will redirect to their corresponding mapped domain.
If one page is attached to multiple domains and a user visits the primary site domain's version of that page, they will be redirected to the version of the page attached to the first domain in your mapping settings.