pandoc/test/command/8098.md

% pandoc -t revealjs --slide-level=2
# Title 1

## Slide 1

Text.

::: fragment
### Sub Slide header

Text.
:::

## Slide 2

Text.
^D
<section>
<section id="title-1" class="title-slide slide level1">
<h1>Title 1</h1>

</section>
<section id="slide-1" class="slide level2">
<h2>Slide 1</h2>
<p>Text.</p>
<div class="fragment">
<h3 id="sub-slide-header">Sub Slide header</h3>
<p>Text.</p>
</div>
</section>
<section id="slide-2" class="slide level2">
<h2>Slide 2</h2>
<p>Text.</p>
</section></section>