Private Sub Button1_Click( _
    ByVal sender As System.Object, _
    ByVal e As System.EventArgs _
) Handles Button1.Click
 
 
        For Each page As TabPage In Me.TabControl1.TabPages
            For Each ctl As Control In page.Controls
                If TypeOf ctl Is LinkLabel Then
                    ctl.Visible = (ctl.Text.IndexOf(txtSearch.Text, StringComparison.CurrentCultureIgnoreCase) <> -1)
                End If
            Next
        Next
    End Sub