The backlog consists of multiple workitems. The filters are used to search over the workitems.
Quick search displays all workitems having their name matched fully or partially to the search text.
To search over workitems by specifying the multiple search criteria,
1. Click on the Add Filter button. It displays all filters available within that view. You can add the filters such as Created by, Priority, Timebox, Tags etc.
2. To remove a filter, place the mouse cursor on a filter and click on the X symbol.
3. Select the filter values and click on the Apply Filter button. It will display all workitems match to the selected search criteria.
4. To remove the selected filter values click on the Reset icon.