DataSet XML Relation : populate parent level instead children :S

Question

DataSet ds = new DataSet();
......
SqlDataAdapter da = new SqlDataAdapter(sql, conn);
da.Fill(ds);
da.Dispose();
XmlDataSource1.Data =  ds.GetXml();
XmlDataSource1.DataBind();

I need XML Data Source from XML for making dynamic ASP:Menu

This code makes DataSource as a Parent element and elements from sql as a Children

I need Parent Elements only from my sql. To make it like a Horizontal TabSet . . .