How to handle user switching groups

I'm building a mobile app (iOS and Android) and users in the app are group-based e.g. one user can belong to multiple groups. Each page data is loaded according to a selected group for each user, this means each page is group dependent. So I want to allow users easily switch groups on every page, rather than firstly navigating to a side drawer or a menu and switch group there. The problem is I am not sure what control/widget (built-in or custom) is a good fit for switching group. I can only think of a few basic built in ones like a dropdown or tabview But putting a dropdown at the top of every page doesn't look pretty and feels a bit odd to me; TabView potentially can work but two of my pages already use TabView, using it for switching group means on these two pages they have nested TabView which might be a confusing.

Wonder whether anyone has any suggestion on this?