Any example on how to use $rx.nav.findNode()

Rhythmyx Implementation Guide has a very shot description on
$rx.nav.findNode
Returns Node
Used in Templates
Starting at the specified node, searches up the navigation hierarchy until it finds a node that has a child node with the specified name.

Does anyone have a working example on how to use the method? I tried different ways, nothing came back to work

Thanks, Hua