Nessus Grep is a perl script which parses the session data files that nessus creates if you have session saving on. Using it you can search the data files for keywords and output the data in text, html, xml.
You can download it from the following link: https://packetstormsecurity.com/files/download/24765/nessus-grep.pl
Source: https://packetstormsecurity.com/files/24765/nessus-grep.pl.html