Using Organic groups 7x-2.7, how can I restrict which users are able to view certain content types?
Group allows for creating arbitrary collections of your content and users on your site, and grant access control permissions on those collections. It is available as of D7, and has a D8 version also. It is designed to be an alternative to Organic Groups. The Group module creates groups as entities, making them fully fieldable, extensible and exportable.
For this specific question, you'd enable the
gnode submodule, and for each group type you would define the appropriate permissions (view, edit, delete, etc) for the various Content Types. That's it.
For more details about how Group compares to Organic Groups, refer to my answer to "What are the features of the Group module versus Organic Group module?".