Click on a test suite's three-dot menu from the Test Directory and select Delete.
Go to Tests > Test Suites.
Click on the three-dot menu of the test suite you would like to delete. It is found at the rightmost column and shows upon hovering.
Alternatively, you could click on the check box then click on Delete in the toolbar that appears. You can select more than one test case using this method.
Click on Delete.
A dialog box asks you to confirm this action. Click Delete.
A toast notification confirms that you've deleted your test suite.