You can remove an applied quick filter in one of the following ways:
To remove a quick filter applied to a single field:
While displaying a filtered list, click the filter icon in the column header where you applied the filter and choose All from the pop-up menu.
To remove quick filters applied to any field:
While displaying a filtered list, in the Condition Panel, click the remove button on the left of the filtering condition.
Besides, you can remove all applied filters from the grid, including quick and advanced ones, at once.