Navigate to Assigned to you. Then you can select all the items you want to assign to Question Submitter and click on Assign option above. A list of Question Submitters will pop up and you can select one.
Assign multiple questions at once
Navigate to Assigned to you. Then you can select all the items you want to assign to Question Submitter and click on Assign option above. A list of Question Submitters will pop up and you can select one.