How do I create a testsuite that adds all tests from a folder and also includes tests from packages contained in the folder?

It seems that I can create a test suite that includes all tests in a folder with the subfolders and I can do the same for a package. But I can't create a suite that starts from a folder and includes all packages contained in the folder. It seems pretty obvious that one would want this feature so I gotta believe the Mathworks has a reason for not providing such a capability ...