Multiple Projects - Seeking seamless navigation and no reauthentication

I have multiple projects on a gateway in a pharmaceutical environment and each project has its own validation requirements.

I am looking for recommendations on the best practice to provide seamless navigation between projects that does not require reauthentication, but authentication is required (for certain functions in certain projects).

I had considered creating a dedicated navigation project that would use embedded views to display the views from the other projects but that got a bit messy with authentication. Another idea was to maybe use Parent projects/inheritance somehow.

Please help!! Any suggestions appreciated!