You can add specific users, departments or workgroups/projects as Feed message recipients.
Suppose you add a private (not visible to non-members) workgroup to a Feed message recipient list. In this case, employees who are not members of this workgroup will see the Hidden recipient sign instead of the workgroup name.
However, all the workgroup members and you, as an author, will see the actual workgroup name in the list of recipients.
The same logic applies to private projects.
Learn more about workgroups and projects
