- Breadcrumbs are used to show the location of the user in the site hierarchy. It is always a secondary navigation for moving in a site.
The current location shown by breadcrumbs are relative to the high level concepts helping users know where they are in relation to the site.
In your case, the two tables are part of Group 0 of the page. The breadcrumb hence must indicate the user "Group 0" which gives fairly good idea about their location in the site. It shows site hierarchy and not users history.
Specifying details further, like Group 1 or Group 2 is unnecessary and it will complicate the design and the very purpose of the breadcrumb.
Having said that, the use of your breadcrumb must be consistent all through out the site in this way.
Hence, coming to the second part of the question, the favorites should contain the page where Group 0. That is whole page. A common use case is, adding a "Page" to Favorites, and not the sections of the page to favorites.