Site Access Restriction (SAR) - Creating Groups and Roles
Controlling Groups and Roles
The plugin can act as a membership plugin and support using roles on a membership level for specific content.
You can add more user roles once installing any WordPress plugin which manage user roles such as User Role Editor https://wordpress.org/plugins/user-role-editor/ which is a free plugin.
Using an external Role Editor plugin you can add multiple roles.
When defining a new role you can base it on an existing role capabilities.
Once adding more roles you can assign specific content to new roles defined by the Content Restriction plugin so only user assigned to the roles can view this content.