Suppose you want to display a bulleted list of forums with their subforums nested beneath them. You want to put this in the wrapper template, or some other template besides the main index. Just use this template code:
<ul>
<!-- BEGIN TOPLIST -->
<CONFIG>forums[,]id[,]5[,]ascending[,]parent=0[,][,][,]0[,]0[,]0[,]0[,]0[,]0[,][,]0</CONFIG>
<li><a href="{CATURL}">{CATNAME}</a>
<ul>
{CATSUBCATS[<li><a href="{CATURL}">{CATNAME}</a></li>]}
</ul>
<!-- END TOPLIST -->
</ul>