My quick answers...
1. Think of it like a neighborhood with several houses. If you are walking down the street (GCC), you can't really see inside the individual houses (subcircle). But, if you are inside the house (subcircle), you can easily look outside and see the street and the rest of the neighborhood (GCC).
2. If the subcircle wants to see the document, as it's created or updated, then include that in the accountability. So, something like, "Notifying @Subcircle when changes are made to document" would work (not the most elegant, but you get the idea).