if you need to place the summary and remaining body in specific places, you can use this.
{% set sections = content.post_body|split('<!--more-->', 2) %}
<div class="this_is_the_summary">
{{ sections[0] }}
</div>
<div>
This is other content between the two.
</div>
<div class="this_is_the_remaining_body">
{{ sections[1] }}
</div>
if you need to place the summary and remaining body in specific places, you can use this.
{% set sections = content.post_body|split('<!--more-->', 2) %}
<div class="this_is_the_summary">
{{ sections[0] }}
</div>
<div>
This is other content between the two.
</div>
<div class="this_is_the_remaining_body">
{{ sections[1] }}
</div>