WP_Query: Query posts only if their access is restricted to logged user’s role

If posts are restricted to a specific role users are required to have, you must add some piece of metadata to the post. Else, WP won’t know which posts you mean.

There’s a standard box for adding metadata to your post (select ‘custom fields’ under ‘screen option’ in your edit screen), or you could create your own metabox or (easier) taxonomy. From your question I gather you already considered the latter option and thought it too cumbersome. But there’s no way to escape putting some tag on the post telling the system which ones are meant for which type of user.

Once there is some metadata on the post, you can query for it.