1. Install the wayFinder package

2. Select the resource which you want to show:

The ‘published‘ resources are shown in drak icon, otherwise light color.

3. Use wayfinder:

<!-- Nav --><nav id="nav">    [[Wayfinder? &startId=`0`&level=`2`]]</nav>

See more: http://rtfm.modx.com/extras/revo/wayfinder

4.Show result:

[MODx] 5. WayFinder