DataTables with child datatable and a column filter

Man123

My Column filter dropdown is not working for the child table..

i am using

initComplete: function () { //create dropdown selection for a column

                var column = this;
                var api = this.api();

                api.columns().indexes().flatten().each(function (i) {
                     var column = api.column(i);

                    var select = $('<select><option value=""></option></select>')
                        .appendTo($(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>')
                    });
                });
            }