How to add a additional Searchfield

BetaOp

I tried to add a Searchfield but it does not work properly

     $(document).ready( function () {
                var table =$('#dataTable').DataTable({
                    responsive: true,
                    "columns": 
    //XYZ
                        ]
                });

    $('#column3_search').on( 'keyup', function () {
                  table
                        .columns( 3 )
                        .search( this.value )
                        .draw();
                } );
            } );

or

    function filterColumn ( i ) {
                $('#dataTable').DataTable().column( i ).search(
                    $('#col'+i+'_filter').val(),
                    $('#col'+i+'_regex').prop('checked'),
                    $('#col'+i+'_smart').prop('checked')
                ).draw();
            }

            $(document).ready( function () {
                var table =$('#dataTable').DataTable({
                    responsive: true,
                    "columns": [
    //XYZ
                        ]
                });

                $('input.column_filter').on( 'keyup click', function () {
                    filterColumn( $(this).parents('tr').attr('data-column') );
                } );
            } );

i tired to make it like this

kthorngren

add a Searchfield but it does not work properly

What exactly happens? Do you get errors in the browser's console?

Looks like your first option should work. Without seeing your complete solution it is hard to say what is wrong. Please post a link to your page or a test case replicating the issue so we can help debug.
https://datatables.net/manual/tech-notes/10#How-to-provide-a-test-case

I did create an example based on your fist code snippet which works:
http://live.datatables.net/ricawovo/2/edit

Kevin