The structure on this article is very similar. In my case, I don’t have a “shared” folder. Any component defined by a parent can be used by any of its children.
The SuperButton.js can use Button.js, but not the reversed. Register/index.js can use SuperButton.js because it defined directly by Register. SuperGreenButton.js can only be used by SuperButton.js.
Parent entities will never use a component defined by a child entity.
Hopefully this helps.