How to add filter for only one column in rad grid ?

Imports Telerik.WinControls.Data
Imports Telerik.WinControls.UI

Public Class Form4
    Private Sub Form4_Load(sender As Object, e As EventArgs) Handles Me.Load
        ' Initialize RadGridView
        Dim radGridView As New RadGridView()
        radGridView.Dock = DockStyle.Fill
        Me.Controls.Add(radGridView)

        ' Set up some sample data
        Dim dataTable As New DataTable()
        dataTable.Columns.Add("ID", GetType(Integer))
        dataTable.Columns.Add("Name", GetType(String))
        dataTable.Columns.Add("Age", GetType(Integer))
        dataTable.Columns.Add("Gender", GetType(String))

        dataTable.Rows.Add(1, "John Doe", 30, "Male")
        dataTable.Rows.Add(2, "Jane Smith", 25, "Female")
        dataTable.Rows.Add(3, "Samuel Adams", 40, "Male")
        dataTable.Rows.Add(4, "Sara Connor", 35, "Female")

        ' Set the data source
        radGridView.DataSource = dataTable

        ' Enable filtering
        radGridView.EnableFiltering = True

        ' Customize filtering with dropdown list
        AddHandler radGridView.CreateCellElement, AddressOf radGridView_CreateCellElement
        AddHandler radGridView.CellEditorInitialized, AddressOf radGridView_CellEditorInitialized


    End Sub
    Private Sub radGridView_CreateCellElement(sender As Object, e As GridViewCreateCellEventArgs)
        If e.CellType Is GetType(GridFilterCellElement) AndAlso e.Column.Name = "Gender" Then
            e.CellElement = New CustomFilterCellElement(e.Column, e.Row)
        End If
    End Sub

    Private Sub radGridView_CellEditorInitialized(sender As Object, e As GridViewCellEventArgs)
        If TypeOf e.ActiveEditor Is RadDropDownListEditor Then
            Dim editor As RadDropDownListEditor = CType(e.ActiveEditor, RadDropDownListEditor)
            Dim element As RadDropDownListEditorElement = CType(editor.EditorElement, RadDropDownListEditorElement)
            If e.Column.Name = "Gender" Then
                element.Items.Clear()
                element.Items.Add("All")
                element.Items.Add("Male")
                element.Items.Add("Female")
                AddHandler element.SelectedIndexChanged, AddressOf DropDownList_SelectedIndexChanged
            End If
        End If
    End Sub

    Private Sub DropDownList_SelectedIndexChanged(sender As Object, e As Telerik.WinControls.UI.Data.PositionChangedEventArgs)
        Dim editorElement As RadDropDownListEditorElement = DirectCast(sender, RadDropDownListEditorElement)
        Dim selectedValue As String = editorElement.SelectedItem.Text
        Dim gridView As RadGridView = DirectCast(editorElement.GridControl, RadGridView)

        gridView.MasterTemplate.FilterDescriptors.Clear()
        If selectedValue <> "All" Then
            Dim filterDescriptor As New FilterDescriptor("Gender", FilterOperator.IsEqualTo, selectedValue)
            gridView.MasterTemplate.FilterDescriptors.Add(filterDescriptor)
        End If
    End Sub

    Public Class CustomFilterCellElement
        Inherits GridFilterCellElement

        Public Sub New(column As GridViewColumn, row As GridRowElement)
            MyBase.New(column, row)
        End Sub

        Protected Overrides Function CreateEditor() As RadDropDownListEditor
            Return New RadDropDownListEditor()
        End Function

        Protected Overrides Sub CreateChildElements()
            MyBase.CreateChildElements()
        End Sub

        Public Overrides Function IsCompatible(data As GridViewColumn, context As Object) As Boolean
            Return TypeOf data Is GridViewDataColumn AndAlso data.Name = "Gender"
        End Function
    End Class
End Class