I have added Juka Zitting's recursive metadata example to the Tika wiki at http://wiki.apache.org/tika/RecursiveMetadata. I also added some notes on what I did so I could get the metadata for a nested document along with the text for that document.
Finally, I modified the http://wiki.apache.org/tika/MetadataDiscussion page to point to the RecursiveMetadata page for a solution for ContentHandler implementers to get access to recursive metadata. I hope this helps. Paul