Hi,
Base on your description, you want to display the menitems like root node, without the childnodes and the parent nodes, right?
Because the sitemap file is an xml file, so it must have a root node in the sitemap file.
But if you can set the sitemapdatasourse's ShowStartingNode is False, the root the node will not be displayed on the page, and you can set all the other node are at the same depth under the root node.
Like below:
<asp:Menu ID="Menu1" runat="server" DataSourceID="SiteMapDataSource1">
</asp:Menu>
<asp:SiteMapDataSource ID="SiteMapDataSource1" runat="server" ShowStartingNode="False" />
Sitemap:
<?xml version="1.0" encoding="utf-8" ?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0">
<siteMapNode title="root" url="" >
<siteMapNode title="Home Page" url="~/Index.aspx" />
<siteMapNode title="Pubs" url="~/...." />
<siteMapNode title="Calendar" url="~/..." />
</siteMapNode>
</siteMap>
Hope it helps.