store(1)->(many)Employee

store(1)->(many)Employee  AND
Empoyee(1)->(many)Child

new PersistenceSpecification<Child>(_session, new CustomEqualityComparerChild())
  .CheckProperty(c => c.Name, "Child1Name")
    --other Child prperties--
  .CheckReference(c => c.Employee, new Employee{
        Store = new Store{--store properties--},
          --other Employee Properties--
        });

Store->Employee->Child

public ReturnOrderMap()
    {
        Id(x => x.Id);
        Map(x => x.OrderTrackingNumber);
        Map(x => x.UserId);

        HasMany(x => x.ReturnOrderLineItems).Inverse().Cascade.AllDeleteOrphan();
    }

 public ReturnOrderLineItemMap()
    {
        Id(x => x.Id);
        Map(x => x.Sku);
        Map(x => x.Status);
        Map(x => x.Comments);

        HasMany(x => x.ReturnOrderReplacementItems).Inverse().Cascade.AllDeleteOrphan();
        References(x => x.ReturnOrder);
    }

 public ReturnOrderReplacementItemMap()
    {
        Id(x => x.Id);
        Map(x => x.Quantity);
        Map(x => x.Size);
        References(x => x.ReturnOrderLineItem);
    }