This can be configured from navigation and security.
so essentially you can show different pages to different roles based on navigation/Homepage and security settings.You can make it look like they are different apps for different users.
To answer ur question Its not possible to build two differnt apps here in one code base and build
but if you want to really do it you can first create one app make changes for second role and they rebuild again that would be overkill.
Its purely Security related , you can have both functionalities in one App .
Navigations added should be restricted with proper user roles
Actually as most of the above comment suggested , I think you do not need two apps , You can create a single app and based on your navigation configuration and security added the users will see what is accessible for them.