I’ve encountered the issue of RecyclerView not be able to scroll inside BottomSheet unless somehow it gets the touch focus, this can be due to both parties RecyclerView and BottomSheetBehavior are interested in horizontal actions.

Basically, you need to care about the state of the Sheet (expanded, collapsed) and disable dispatching touch events to the parent or disabling nested scrolling if the RecyclerView can’t scroll in any direction. I haven’t tried this myself. I’m just giving you pointers where you should be addressing your issue: touch event handling, touch focus dispatching.

Adding ViewPager should not be significantly problematic, especially the part of touch event handling. Try to avoid adding Fragments inside BottomSheetDialogFragment. That would be really nasty.

Cheers!