How to create nested posts (posts within a post) in WordPress?

Hi,

I would like to create both individual posts (which are essentially articles) and category posts (which get listed like posts, but have posts under them as well).

The idea is the following: a travel blog with posts within posts.

Some posts are entire trips (with multiple posts under them), others are just single articles.
All get directly posted under the main category (let's say "my travels").

Trips would have a different look with a different button….

How to create nested posts (posts within a post) in WordPress?