I tested it and with these settings it works to have only domainname without path:
config setprop wordpress DomainName testserver.cmb.local
Now I can access wordpress without path like
Maybe the picture in the wiki was irritating because it shows a WordPress Address (URL) like
For having different path:
config setprop wordpress URL blog
BTW, you can empty a value like this:
config setprop wordpress DomainName ''