If you have a model that has a ModelLink to another model then you can apply for related model permissions. When you choose this type of Permission, you are saying "I can read this model if I can read this other model which it is linked to", or "I can write this model if I can write the other model it is linked to." Within RelatedModel permission, the different models selected are OR'd when determining access, similar to dimension permissions. This means you need only match one of those models to get permission.
In the above example, we have provided read permission to ZBKS.SampleRoleType based on ValueChain dimension permission and RelatedModel permission to SalesRep field (which is a User ModelLink field on Book model) and Supplier field (which is an Organization ModelLink field on Book model).
Recursive permissions are possible with RelatedModel permission.