<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="OrgChartControl.ascx.cs" Inherits="RadOrgChartTest.OrgChartControl" %>

<%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI" %>
    <telerik:RadScriptManager runat="server" ID="RadScriptManager1" />
    <div>
        <telerik:RadOrgChart runat="server" ID="RadOrgChart1" Skin="Office2007">
            <ItemTemplate>
              
                            <asp:ImageButton ID="ZoomToButton" runat="server"
                                Style="cursor: pointer"
                                CommandArgument='<%# DataBinder.Eval(Container.DataItem, "Id")%>'
                                OnClick="ZoomToButton_OnClick"
                                Visible='<%#Eval("NotLastClicked")%>' />
                          
            </ItemTemplate>
        </telerik:RadOrgChart>

       </div>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace RadOrgChartTest
{
    public partial class OrgChartControl : System.Web.UI.UserControl
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            update(0);
        }

        private void update(int LastClicked)
        {
           RadOrgChart1.DataTextField = "Label";
            RadOrgChart1.DataFieldID = "Id";
            RadOrgChart1.DataFieldParentID = "Parent";

            RadOrgChart1.DataSource = GetDataFromDatabase(LastClicked);
            RadOrgChart1.DataBind();
       
        }

        protected void ZoomToButton_OnClick(object sender, EventArgs e)
        {
            update( int.Parse(((ImageButton)sender).CommandArgument));
        }

        private class FakeData
        {
            public string Label {get;set;}
            public int Id {get;set;}
            public int? Parent {get;set;}
            public bool NotLastClicked {get;set;}
        }

        private List<FakeData> GetDataFromDatabase(int LastClicked)
        {

            List<FakeData> r = new List<FakeData>();
            r.Add(new FakeData { Label = "Parent", Id = 1, Parent = null, NotLastClicked = LastClicked!= 1 });
            r.Add(new FakeData { Label = "Node a", Id = 2, Parent = 1, NotLastClicked = LastClicked != 2 });
            r.Add(new FakeData { Label = "Node b", Id = 3, Parent = 1, NotLastClicked = LastClicked != 3 });
            r.Add(new FakeData { Label = "Node c", Id = 4, Parent = 1, NotLastClicked = LastClicked != 4 });
            r.Add(new FakeData { Label = "Node d", Id = 5, Parent = 1, NotLastClicked = LastClicked != 5 });

            return r;
        }

    }
}