I can open Yelp to a specific man page as follows:
yelp man:bash &
But how can I use Yelp to browse (view a list of all man pages and open them one by one) and search (find all man pages that contain a given string)?
The search feature in yelp is broken and does not include man pages in the results. See https://bugzilla.gnome.org/show_bug.cgi?id=505641
This is unsatisfying, but You can press
[Ctrl]+[L] and enter the man page to display, e.g.