How to reproduce:

• Create a content type with
  • an attribute of type content, specifying a content type
  • a view containing this attribute
  • add subitems into this reference
• In content types editor tool,
  • open your content type
  • Expand the view,
    • you can see your content attribute => OK
    • But you can not see the subitems => KO

Warning: should also work for a property (not an attribute) of type content