How to clear dropdown filters of datatables

khubab

Here is my code using drpodown filters

$(document).ready(function() {

$('#example1').DataTable( {
dom: 'Bfrtip',
buttons: ['excel'],
lengthChange: true,
paging: false,
scrollY: 520,
scrollX: false,
sScrollXInner: "190%" ,

    initComplete: function () {
        this.api().columns().every( function () {
            var column = this;

            var select = $('<select><option value=""></option></select>')


                .css('width',85)



                .appendTo( $(column.footer()).empty() )
                .on( 'change', function () {
                    var val = $.fn.dataTable.util.escapeRegex(
                        $(this).val()
                    );

                    column
                        .search( val ? '^'+val+'$' : '', true, false )
                        .draw();
                } );
            column.data().unique().sort().each( function ( d, j ) {
                select.append( '<option value="'+d+'">'+d+'</option>' )
            }
              );
        }             
         );
    }      
} );
          } );