The Shared Projects list in the Dashboard shows you a summary of your Arkit projects, which companies they are assigned to, and how many projects are currently being shared.
In the main Projects list in the Dashboard, each project is also labeled with "Shared" or "Not Shared".
In any project, the Summary panel displays information about the Assigned Company and whether the project is being shared. If the project is being shared, the number of collaborating users at the assigned company is also displayed. Additional people at the assigned company may have access to your shared projects, depending on their user roles.