Making a datatable, maybe also with column filters
Use some variables. You don't need to chain function calls; it's just a neat thing you can do when appropriate, but it's not required.

$('#dt_a').each(function() {
  var target = $(this), // store this 
      table  = target.dataTable({  // and store this too
          "sDom": "&lt;'row'&lt;'span6'&lt;'dt_actions'&gt;l&gt;&lt;'span6'f&gt;r&gt;t&lt;'row'&lt;'span6'i&gt;&lt;'span6'p&gt;&gt;",
          "sPaginationType": "bootstrap_alt",
          "oLanguage": {
              "sLengthMenu": "_MENU_ records per page"
          }
      });

    if (target.hasClass('trans')) {
        table.columnFilter({
            sPlaceHolder: "head:before",
            aoColumns: [
                null,
                { type: "text" },
                { type: "text" },
                { type: "date-range" },
                { type: "text" },
                { type: "text" },
                null,
                null
            ]
        });
    }
});