Display only the root nodes with MVCSiteMap - asp.net-mvc-3

Question

I am using Asp.net MVC SiteMap Provider to manage the sitemap of my website.
Structure of Application:
It is a small application where I have an area called "Admin"
SiteMap
<mvcSiteMapNode title="LET'S GO" controller="Home" action="Index">
<mvcSiteMapNode title="FESTAS" controller="Festas" action="Index">
<mvcSiteMapNode title="INFANTIL" controller="Festas" action="Infantil" />
<mvcSiteMapNode title="ADULTO" controller="Festas" action="Adulto" />
</mvcSiteMapNode>
<mvcSiteMapNode title="ORÇAMENTO" controller="Home" action="Index" />
<mvcSiteMapNode title="CONTATO" controller="Home" action="Contato"/>
<mvcSiteMapNode title="ADMINISTRAÇÃO" area="Admin" controller="Home" action="Index">
<mvcSiteMapNode title="FESTAS" area="Admin" controller="Festas" action="Index" />
<mvcSiteMapNode title="SUBSIDIÁRIAS" area="Admin" controller="Subsidiarias" action="Index" />
</mvcSiteMapNode>
</mvcSiteMapNode>
Problem
To display the main menu, use the following command:
#Html.MvcSiteMap().Menu()
This is the first problem, all nodes are displayed.
I would like to display only the nodes roots ("INFANTIL" and "ADULTO" for example will not be displayed)
The nodes of the Admin area can not be displayed. They only appear on another view.
How can I accomplish these tasks?
Question
How can I generate a sitemap only a specific node?
Example: I want to generate the sitemap only child node of "ADMINISTRAÇÃO"
Thanks to everyone!!

Answer 1

1) I would like to display only the nodes roots ("INFANTIL" and "ADULTO" for example will not be displayed)
#Html.MvcSiteMap().Menu(1, 1)
2) The nodes of the Admin area can not be displayed. They only appear on another view.
May be you should use roles attribute.
Creating a first sitemap
How can I generate a sitemap only a specific node?
Try to use one of the overloaded method
public static System.Web.Mvc.MvcHtmlString Menu(this MvcSiteMapProvider.Web.Html.MvcSiteMapHtmlHelper helper, System.Web.SiteMapNode startingNode, bool startingNodeInChildLevel, bool showStartingNode, int maxDepth)

Answer 2

I know this question is bit outdated, but for future use:
this can easily be done by decorating the Actions (or Controller) with access permissions.
I assume that not everybody can access the administrative part (only the accredited). So you could create eg an Administrative Role and decorate with a FilterAttribute the Actions (or Controller): eg
[Authorize(Roles = "Administrator")]
public ActionResult Index()
{ .... }
Once the user has identified herself as an Administrator the sitemap entry for the Index Action will be shown.