@gregfielding
Check out this thread. You can adapt the code provided for xprofile fields by simply replacing the ul class with `table.profile-fields`.
https://buddypress.org/community/groups/how-to-and-troubleshooting/forum/topic/make-drop-down-menu-links-open-in-new-page/
There are also several plugins that might get the job done too, but you may have to fiddle with them. Search the wp repo for “Open external links in a new window” for a few examples.
While I understand your desire in this respect it ought to be pointed out that this is frowned on practice, although I have always kept a script snippet in library files for this purpose to hook onto rel=”ext” links, opening new windows or tabs has NOTHING to do with the web author/ developer it is NOT their concern how a user wants to have pages open in their browser, it is entirely a User based function and as responsible developers we do not attempt to impose on how a users browser functions. As a user nothing will displease me more nor have me leaving a site faster than a web site that attempts to modify my browsing habbits.
Having said that I always set new windows to open as a new tab, oh and the reason new windows are particularly bad? A new window has no browsing history thus no back button , a new window tends to open exactly overlapping the previous one, this can be extremely confusing for very many less experienced web users especially the older generation.
@hnla
Those are valid points. I also tend to open off-site links in new tabs (especially when researching, scrounging or learning new code bits 
), so I can jump between sites without losing track of previously visited stuff. But, as you say, members of older generations (like my step-mother), or those not-too-tech-savvy (like my employer) can get confused when windows open automatically and overlap each other.
It’s also true that this should be left to the user to decide. I agree, if links are set to open in new windows/tabs, this MUST be indicated to the user with a text message or icon.
Yes good point; accessibility requirements dictate that links should be clearly marked as ones that open off site links/new windows.
