If you do not see a target, Team Hub, Project, or Class you expected to be shared with you, contact the author and make sure they have created these linkages between the target, Team Hub, and Project/Class.  

Targets and sessions must be made visible to the Team Hubs by the creators. For example, if you create a Target, you need to look at the Target Gallery and “Manage Visibility” to make the target visible to a Team Hub.