Sometimes you want to show the parent categories of the active node. And usually you want to show the current categories at a fixed depth.
To do this the list of parents is loaded into the $parents variable. Here, $parents.0 is the root node, and $parents.1 is the first node from the root towards the current node. This example uses childrenof=$parents.2, which means nodes at level 3 will be listed (root is on level 0).
{assign var=parents value=$node->get_parents(true)}
{if $parents.2}
<ul>
{list childrenof=$parents.2}
<li>{$title|escape}</li>
{/list}
</ul>
{/if}