First you use Freetextbox then get Freetextbox.dll for it and also write down code on page header

<%@ Register TagPrefix="FTB" Namespace="FreeTextBoxControls" Assembly="FreeTextBox" %>

Nestedrepeater.aspx

HTML / XML
 <div>       	
			<asp:Repeater ID="FtbRepeater1" runat="server">
				<ItemTemplate>
					<FTB:FreeTextBox id="FreeTextBox1" Text='<%# DataBinder.Eval(Container.DataItem, "value") %>' 
						runat="Server" />
				</ItemTemplate>    	
				<SeparatorTemplate>
					<hr />    	
				</SeparatorTemplate>
			</asp:Repeater>
    	
			<asp:Button id="SaveButton" Text="Save" onclick="SaveButton_Click" runat="server" />
		</div>
		<div>
			<asp:Literal id="Output" runat="server" />
		</div>

Nestedrepeater.aspx.cs

C#
 protected void Page_Load(Object Src, EventArgs E) {
	if (!IsPostBack) {

		ArrayList stuff = new ArrayList();
		stuff.Add(new ListItem("Hey", "<b>asdasdf</b>"));
		stuff.Add(new ListItem("Yo", "<i>italic</i>"));

		FtbRepeater1.DataSource = stuff;
		FtbRepeater1.DataBind();

	}
}

protected void SaveButton_Click(object sender, EventArgs E) 
{
	Output.Text = "";
       foreach (RepeaterItem repeaterItem in FtbRepeater1.Items) {
     FreeTextBox FreeTextBox1 = repeaterItem.FindControl("FreeTextBox1") as FreeTextBox;
     Output.Text += FreeTextBox1.Text + "<hr />";
	}
}