$$ components
{% component outer(title) %}
<div class="outer">
<h1>{{ title }}</h1>
{{ body | safe }}
</div>
{% endcomponent outer %}
{% component inner(text) %}
<p class="inner">{{ text }}</p>
{{ body | safe }}
{% endcomponent inner %}
$$ tpl
{% <outer title="Hello"> %}
Before inner
{% <inner text="World"> %}
Nested content
{% </inner> %}
After inner
{% </outer> %}