The filter widget allows you to preset commonly used filters.
The Quickfilter widget is available in the advanced configuration tab.
Once you've selected the widget and see the screen as pictured above, you can select a category from the dropdown menu in the leftmost field, an operator in the center field and optionally an operand in the rightmost field. If you select an operand, the filter will be displayed in green and function as a button. If you leave the operand empty, the filter will remain grey and users will be able to choose the value of the filter from a dropdown menu.
You can add as many Quickfilters to this widget as you like.