Deleting a Filter or Value Field can be done in two ways (for simplicity's sake, filters and value fields will be referred to as elements).

2.1 Delete selected item

Select a row in the grid → click the "Delete selected item" button (text may vary depending on the selected language).

This method will delete any editable elements represented by the row.

2.2 Delete a single filter using The Details panel

A more finely grained approach to deleting an element can be done by using the Details panel: select a row in the grid → expand the Details panel if it is collapsed → click on the "Delete" button for the element you want to delete:

Deleting the Keywords-AllInList filter.