In the bottom of the activation I use BottomNavigationView . It contains two tabs, each of which contains its own fragment. These two fragments contain TabLayout on top, for each fragment it is different. In TabLayout there can be several tabs, and each tab contains its own fragment with content.
Question. How to implement it architecturally. Create Tab fragments from BottomNavigationView fragments. Or make the BottomNavigationView fragments activities inside the main parent activity. And then I heard a lot where the connectedness of fragments is evil, and it is not good to launch a fragment from a fragment.

