uses
  XMLDoc, XMLIntf;

procedure TForm1.Button1Click(Sender: TObject);
var
  BodyNode: IXMLNode;
  Level1Node: IXMLNode;
  Level2Node: IXMLNode;
  XMLDocument: IXMLDocument;
begin
  XMLDocument := NewXMLDocument;
  BodyNode := XMLDocument.AddChild('body');
  Level1Node := BodyNode.AddChild('level1');
  Level2Node := Level1Node.AddChild('level2');
  Level2Node.Text := 'text';
  Level2Node := Level1Node.AddChild('level2');
  Level2Node.Text := 'other text';
  XMLDocument.SaveToFile('c:\File.xml');
end;