pdf_split_bookmark-pdftk
This utility reads bookmarks using PDFTK, then splits based on a specified bookmark level.
You will need the pdftk binaries from Sid Steward (http://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/).
Caveat: Bookmarks should start a new page.
Usage:
pdf = PDF.new('foo.pdf')
pdf.split_by_bookmark_at_level(2)
Optionally specify an output directory:
pdf.split_by_bookmark_at_level(2, '/dev/null')