@Entity
@Audited
public class EntityA {
    ...
    private EmbA emb;
    ...
}

@Embeddable
public class EmbA {
    ...
    @ManyToMany
    private List<EntityB> entityBList;
    ...
}

@Entity
@Audited
public class EntityB {
    ...
    @ManyToMany(mappedBy = "emb.entityBList")
    private List<EntityA> entityAList2;
    ...
}

//org.hibernate.envers.configuration.internal.metadata.CollectionMetadataGenerator.java
//line: 945
private String searchMappedBy(PersistentClass referencedClass, Table collectionTable) {
    final Iterator<Property> properties = referencedClass.getPropertyIterator();
    while (properties.hasNext()) {
        final Property property = properties.next();
        if (property.getValue() instanceof Collection) { //it skip the embeddable property which may contains relation property.
            ...
        }
    }
}