Recent releases of Xamarin Forms have added a new framework for building navigational elements called 'Shell'.
https://docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/shell/
This framework facilitates building complex navigational elements in mobile applications.
Currently TestComplete cannot see controls beyond the top level object 'Navigation Shell'. As Xamarin is moving forward with this as their primary way to create navigation systems within Forms it should be considered for support in TestComplete.