You can now map a domain to a specific Archive, Category, or Custom Taxonomy, including all descendant posts.
Here's a video explaining all about Category/Archive mapping:
In order for all posts within an Archive, Category, or any kind of Custom Taxonomy, you can simply map the corresponding item to the domain and then enable the checkbox for Global Archive Mapping.
When this functionality is enabled, all posts within any mapped Archive, Category, or Mapping will take on the mapped domain.
When activated simultaneously with Global Domain Mapping, website visitors will only be able to view the posts using the mapped domain.