Kendo Grid Filterable cell

There are a few different parts to this.

First, if you want to have multiple filter controls for different pieces of data, you should define a column for each one. Then, put a template on the first column to have it display the data for two columns. Use the attributes option to set a colspan=2. Then, use the attributes option on the second columns to set style="display:none".

The second part is getting the dropdowns. I generally prefer to use the "values" option to accomplish this. The code below uses this for the OrderID column. The other alternative was the approach you were on, which is to use the cell template. The code below uses this on the ShipName column.

    <div id="example">
        <div id="grid"></div>
        <script>
            $(document).ready(function() {
                $("#grid").kendoGrid({
                    dataSource: {
                        type: "odata",
                        transport: {
                            read: "http://demos.telerik.com/kendo-ui/service/Northwind.svc/Orders"
                        },
                        schema: {
                            model: {
                                fields: {
                                    OrderID: { type: "string" },
                                    Freight: { type: "number" },
                                    ShipName: { type: "string" },
                                    OrderDate: { type: "date" },
                                    ShipCity: { type: "string" }
                                }
                            }
                        },
                        pageSize: 20,
                        serverPaging: true,
                        serverFiltering: true,
                    },
                    height: 550,
                    filterable: {
                        mode: "row"
                    },
                    pageable: true,
                    columns: 
                    [{
                        field: "OrderID",
                        width: 150,
                        attributes: {
                            colspan: 2
                        },
                        values: [{text: "10248", value: "one"},{text:"10249", value: "two"}],
                        template: '#:OrderID# (#:ShipName#)',
                        filterable: {
                            cell: {
                                operator: "eq",
                                showOperators: false
                            }
                        }
                    },
                    {
                        attributes: {
                            style: "display:none"
                        },
                        field: "ShipName",
                        width: 200,
                        title: "Ship Name",
                        filterable: {
                            cell: {
                                template: function(args) {
                                    args.element.kendoDropDownList({
                                        dataSource: args.dataSource,
                                        dataTextField: "ShipName",
                                        dataValueField: "ShipName",
                                        valuePrimitive: true
                                    });
                                },
                                operator: "eq",
                                showOperators: false
                            }
                        }
                    },{
                        field: "Freight",
                        width: 255,
                        filterable: false
                    }
                  ]
                });
            });
        </script>
    </div>

Runnable Demo