I am  using Examine search for the site search function,

In that i don't reterive the chilnode in the C#,

Examine.Config section

<add name="school"/>

//EventHandler section

 public ExamineEvents()

 {

 var studentIndex= (LuceneIndexer)ExamineManager.Instance.IndexProviderCollection["studentIndex"];

studentIndex.GatheringNodeData += new EventHandler<IndexingNodeDataEventArgs>(studentIndex_GatheringNodeData);

}

 //To Get All the Node Values

private void studentIndex_GatheringNodeData(object sender, IndexingNodeDataEventArgs e)

{

    var node = uQuery.GetNode(e.NodeId);//geting the Node ID
     if (node != null)
      {
         IEnumerable<Node> schools = node.GetChildNodesByType("Education");//identity child node
          if (schools.Any())
           {
              var School = new StringBuilder();
              foreach (Node school in schools)//getting the all the properties
               {
                    School.Append(school.Name).Append(" ");//append the school Name
                }
                e.Fields.Add("school", School.ToString());//Append the School Name as the node
             }
        }

}