It's my very first time to use BottomSheetDialog,
the code is like this:
final BottomSheetDialog bottomSheetDialog = new BottomSheetDialog(this);
If you look into the source code of
android.support.design.widget.BottomSheetDialog you will find, that inside it's constructor there is a line:
// We hide the title bar for any style configuration. Otherwise, there will be a gap // above the bottom sheet when it is expanded. supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
which clearly states, that Bottom sheet will not have title (with reason). (As of support library version 23.4.0)
Suggestion: Make a title of the view inside the layout of bottom sheet.