Composite control represents multiple attributes on form. Its saves the space on the form. It expands and shows all the fields on clicking it.
Composite control display behavior is different from Web and Mobile clients. it will show all the attributes that are part of the composite attribute in Mobile/Tablet app. This is the limitations with Composite controls in Mobile app.
We need to manage client side code separately for composite control in web and mobile client.
Please find below link for list of Composite controls in Dynamics 365 and also managing client API separately from both the clients (Web and Mobile).