I have a large site and I am using 2 menus the primary navigation I would like to limit to level 2

then in pages other than landing pages and the home page I will add a second "context" menu that will let the user drive deep as they navigation that section of the site

here is what I am trying now 

<dnn:NAV runat="server" id="dnnNAV" 
providername="DNNMenuNavigationProvider" 
indicatechildren="true" 
controlorientation="Horizontal" 
csscontainerroot="nav_container" 
csscontainersub="nav_submenu_container"
cssnoderoot="nav_rootitem" 
cssnodehoverroot="nav_rootitem_hover" 
cssnodeselectedroot="nav_rootitem_selected" 
cssnode="nav_item"
cssnodehoversub="nav_item_hover"     
cssnodeselectedsub="nav_item_selected" 
csscontrol="nav_bar" 
cssbreak="nav_break" 
cssicon="nav_icon"   
Level="Root" 
ExpandDepth="1" 
>
<CustomAttributes>
<dnn:CustomAttribute Name="RenderMode" Value="UnorderedList" />
</CustomAttributes>
</dnn:NAV>

the highlight text is what I am trying to figure out to get the primary nav to stop at level 2

any help would be great