I use the symbol browser in the left pane to show and navigate to "sub" functions when authoring a Perl module.
Unfortunately, if I name my subs using namespaces (such as modname::misc::funcname), geany will only display the part of the name to the left of the "::" (in my example: "modname"). This makes it impossible to navigate to those functions.
C++ has a similar problem, but not quite the same. I don't recall what it was though. :-)