There's an Export All Processes option in DataPump, which exports the XML details of each process. However, this doesn't do much more than capture the sequence of projects, and the distributions of the exports. The model files are only reference in the XML project files itself, as are the input files. The model files contain the details of external lookups, filters, and so on.
You _can_ recurse through the job logs to get the sequence of projects and then parse the XML xprj files for the reference to xmods and try to glue the whole thing together. Or if you upgrade to DataPump v11, then the job logs are verbose and contain all the information you need.
I would like to say that upgrading to v12 or v13 would help, but the introduction of the Digital Object Repository meant that instead of references to:
...we are faced with:
which isn't quite so helpful.
I'm hoping to get to grips with the issue a bit more in Q1 - because I've built a utility that generates editable Visio flow diagrams from job logs and it's a shame to see it go to waste. If you'd like to see a sample of the output from a v11 job log, please do let me know.