You'd need an add-on to automatically do it, not sure if one exists.
You can do a basic HTML widget though:
Code:
<ol class="categoryList is-active">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="CATEGORYLINKHERE" class="categoryList-link">
Category 1
</a>
</div>
<ol class="categoryList is-active" tabindex="-1" style="">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #1
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #2
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #3
</a>
</li>
</ol>
</li>
</ol>
<ol class="categoryList is-active">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="CATEGORYLINKHERE" class="categoryList-link">
Category 2
</a>
</div>
<ol class="categoryList is-active" tabindex="-1" style="">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #1
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #2
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #3
</a>
</li>
</ol>
</li>
</ol>
Result was:
View attachment 190033
or:
Code:
<ol class="categoryList toggleTarget is-active">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a class="categoryList-toggler" data-xf-click="toggle" data-target="< :up :next" role="button" tabindex="0" aria-label="Toggle expanded"></a>
<a href="CATEGORYLINKHERE" class="categoryList-link">
Category 1
</a>
</div>
<ol class="categoryList toggleTarget" tabindex="-1" style="">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #1
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #2
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #3
</a>
</li>
</ol>
</li>
</ol>
<ol class="categoryList toggleTarget is-active">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a class="categoryList-toggler" data-xf-click="toggle" data-target="< :up :next" role="button" tabindex="0" aria-label="Toggle expanded"></a>
<a href="CATEGORYLINKHERE" class="categoryList-link">
Category 2
</a>
</div>
<ol class="categoryList toggleTarget" tabindex="-1" style="">
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #1
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #2
</a>
</div>
</li>
<li class="categoryList-item">
<div class="categoryList-itemRow">
<a href="NODELINKHERE" class="categoryList-link">
Node #3
</a>
</li>
</ol>
</li>
</ol>
View attachment 190034