How to show all nodes and comments by a user in a single view?
This is an example of my setup, just switch out article or content type for your content type or forum posts.

node--article--teaser.html.twig:

&lt;div class="{{ node.type.0.target_id | clean_class }}-teaser-wrapper" {{ attributes }}&gt;

    {# other fields #}

    {{ content.field_comments }}

&lt;/div&gt;


or:

&lt;div class="{{ node.type.0.target_id | clean_class }}-teaser-wrapper" {{ attributes }}&gt;

    {{ content }}

&lt;/div&gt;


As long as the comment field is set to display in your teaser view mode, and printed via your template, the comments will show in the view results.

View Config:



The contextual filter is the important part.





This setup uses content format teaser, the alternative would be using fields. Both will work, with fields you may need a relationship to comments depending on what fields you need available in your view.