How to create nested publications (publications within a publication) in WordPress?


I would like to create both individual publications (which are essentially articles) and post categorys (they are listed as publications, but they also have publications below them).

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

Some publications are complete trips (with multiple publications under them), Others are just individual items.
All are published directly in the main category (let's say "my trips").

The trips would look different with a different button.

But, essentially, they would all look like messages.
When you click on a travel publication, you will find more individual posts under them or … sometimes you could find more trips and another level below the individual items.

Let me list an example of the structure:

"Summer trip to Spain" [trip]
> "Trip to Catalonia" [trip]

>> "The best places to visit in Catalonia" [article]
>> "Why is Catalonia famous?" [article]
>> "The best museums to visit in Catalonia" [article]
> "Exploring Madrid" [trip]
>> "Cultural Heritage of Madrid" [article]
>> "Photos of Madrid street" [article]
> "Visiting Valencia" [trip]
>> "The best beaches of Valencia" [article]
>> "The old town of Valencia" [article]

"The best airlines in the United States" [article]

"My favorite airports" [article]

"Visiting Cuba" [trip]
> "The Havana experience" [trip]
>> "Magic streets of Havana – Photo gallery" [article]
>> "What to do and what not to do in Havana" [article]
>> "Cultural Heritage of Havana" [article]
> "The best beaches in Cuba" [article]

"The best European cities to visit in 2019" [article]

Basically, some are nested under others, but I never want to go down more than 3 levels. 3 is the maximum.

I will make sure to distinguish ARTICLE TRIP by design. They will look differently.

I intend to use Elementor to create a WordPress theme, but I have not found a way to "nest" the posts one below the other.

How I can get this?