Creating a test suite/nested test suite
To create a test suite, select a test plan or root suite and press the Create test suite button.
Suites-adding based on the sections
There is a way to create suites based on the test library section, in this case, the system will ask to select the tests that will be in the test plan. After saving, the selected tests will be added to the test-plan in the structure of related test library section.