Steps (AddTest -> User Group (Removal)):

  1.  Navigate to 'Add Test' or 'Edit Test' page from the 'Tests > Tests List'. 
  2.  Go to the 'Assignment Information' section and in it see the selected group(s) under the '+ Users Group' button.
  3.  Click on either of the buttons listed below:
    1. 'Remove All' (If you have to remove all the groups then click on it.),
    2. 'Remove' (If you have to remove the particular group then click on it).
  4.  After that, a modal window will be popped up asking for the confirmation of removing the group(s).
  5. Click on the 'Yes' button to remove. If not then click on the 'No' button.