Writing full, absolute path to file field


I previously had used relative links for attached PDFs. So the File field in the .bib file was along the lines of “:Jones-2002.pdf:pdf” I now want to switch to an absolute directory for my attachments, but don’t see how to make JabRef change the File field in the .bib file accordingly. I’d like it to now read “/Users/Groucho/PDFs/Jones-2002.pdf:PDF”. Can anyone tell me how to accomplish this, please?

Thank you.