protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
Repeater repeater2 = e.Item.FindControl("Repeater2") as Repeater;
if (repeater2 != null)
{
repeater2.DataSource = yourDataSource;
repeater2.DataBind();
}
}
}