Specifying tenant using SessionBuilder.tenantIdentifier() vs CurrentTenantIdentifierResolver - when to use one vs the other?

Question

I'm reading the docs on multi-tenancy in Hibernate and there seem to be two ways that you can specify a tenant identifier.

The first way is by calling SessionBuilder.tenantIdentifier() every time you open a session:

Session session = sessionFactory.withOptions()
        .tenantIdentifier(yourTenantIdentifier)
        ...
        .openSession();

The second way is by specifying a custom CurrentTenantIdentifierResolver, by either passing it to the Configuration via its setCurrentTenantIdentifierResolver() method, or by using the hibernate.tenant_identifier_resolver setting:

public class MyCustomResolver implements CurrentTenantIdentifierResolver {
    @Override
    public String resolveCurrentTenantIdentifier() {
        // TODO implement
    }

    @Override
    public boolean validateExistingCurrentSessions() {
        return false;
    }
}

My question is, when should we use one approach vs the other? What is the advantage/disadvantage of each approach? Also if you use one, should you avoid using the other or can they both be used at the same time?