Using Zephyr in a master - client project test suite setup

Hello everyone,

A test manager in my organization has issues with Zephyr for the specific context of the project he's working on. The project is set up as one "master project", which contains the test library, and multiple "client projects" for each client organization that is included in the testing of the software. Client's results are stored in these projects so that they do not have access to each other's data and test results, which is a requirement of the project. Another requirement is that testers cannot have access to the full master project, as not all tests defined in the master project are valid for all clients. 

It would appear that copying these test cases from the master into a test cycle of one of the client project does require the user to have permissions on the master project. A user that only has permissions on their own client project runs into errors due to the fact that they have no permissions on the master project.

Is there a way to configure Zephyr so that testers in the client projects can use the tests defined in the master project without allowing them access to the full master project?

Thank you for your help.