Currently directories don’t exist in the graph. @decentralion and @wchargin have spent a while talking about how we could have a “directory plugin” which treats git directories as graph nodes, connects them to PRs which modify directory contents, etc. However, there are challenging problems around how to identify directories across revisions and renames, and we never prioritized this area of research, so we are still pretty far from having such a plugin.
One very interesting scenario for this feature I think is mentioned here, Experiment: SourceCred stack lookup Multi-repo setups.