iPhone 15.3.1 Folders inside folders

Has anybody managed to nest folders inside a folder? Example: I wish to make a TRAVEL folder on the home screen, inside of which I want 3 folders - Lodgings, Transportation, Sightseeing.

I have been adviced to do this inside the FILES app, but on my phone none of the folders or apps I wish to move/combine appear in the FILES.

When I make a new folder in FILES it just sits there.

On the home screen I can't slide a folder into another folder.

Advice would be much appreciated.