Is it ok to use Bottom Nav Bar with Tabs for sub-level?

I am trying to design and app with Material design which has 6 top level destinations and 4 of them have sub-levels.

1. Is it ok to use Bottom nav bar for 5 of them and put 6th one in side navs along with some more options like profile, logout, & help & policy?
2. Is it ok to use top tabs for sub levels along with bottom nav and side nav?
3. Is it ok to use same design for iOS apps as well?