Need some help with virtual (fake) posts with custom url

Hi
I have a big deal of posts with similar structure of data.
Example
-content
—posts
------post1.md
------post2.md
------post3.md
etc with urls:
www.mysite/post1
www.mysite/post2
www.mysite/post3
I need to add to each post 3 additional (child) pages with the same data, but with other template and child url.
www.mysite/post1/post1-subpost1
www.mysite/post1/post1-subpost2
www.mysite/post1/post1-subpost3

How can I do this?
Something like this doing plugin for wordpress:
https://return-true.com/creating-a-custom-page-with-wordpress-endpoints/

Sorry, we don’t answer questions like this in #support. You are encouraged to read the docs, experiment, and ask questions about specific walls you’ve hit.

Your post is difficult to understand, so please put together a project and show us what you’ve tried. Thanks! :slight_smile: