dotCMS Flat Navigation Example (not tested)

flatnav.vtl

## Define a macro to handle the children
#macro(navFlatChildren $nav_children, $level)
  #foreach($nav_item in $nav_list)
    #if(!$nav_item.folder && $UtilMethods.isSet($nav_item.href))
      ## so we are not a folder and we have a url so show a link
      <li><a href="${nav_item.href}">$nav_item.title</a></li>
    #else 
      #if($nav_item.folder
            && $nav_item.children
            && $nav_item.children.size() > 0
            && $levels_deep > $level)
        ## Now we have a folder with children so show it's children
        #navFlatChildren($nav_item.children, $math.add(level,1))
      #end
    #end
  #end
#end

## Pull the top level nav items
#set($nav_list = $navtool.getNav("/"))

## You are going to want to set some sort of limit of how deep to go
#set($levels_deep = 5)

## You might also consider using #dotCache around this whole chunck,
## it has the potential to be a heaver chunck of code.
  
<ul>
  #foreach($nav_item in $nav_list)
    #if(!$nav_item.folder && $UtilMethods.isSet($nav_item.href))
      ## so we are not a folder and we have a url so show a link
      <li><a href="${nav_item.href}">$nav_item.title</a></li>
    #else 
      #if($nav_item.folder
            && $nav_item.children
            && $nav_item.children.size() > 0
            && $levels_deep > 1)
        ## Now we have a folder with children so show it's children
        #navFlatChildren($nav_item.children, 2)
      #end
    #end
  #end
</ul>