columns.filterable.extra Boolean (default: true)

If set to true the filter menu of the column allows the user to input a second criterion.

Example - disable the second filter criterion for the name field.

<div id="grid"></div>
<script>
  $("#grid").kendoGrid({
    columns: [
      { field: "name" , filterable : { extra: false }},
      { field: "age" }
    ],
    filterable: true,
    dataSource: {
     data: [ { name: "Jane", age: 30 }, { name: "John", age: 33 }],
      schema:{
        model:{
            fields: {
                age: { type: "number" }
              }
          }
      }
    }
  });
</script>