Sorry for the late reply, I tried both versions (with and without parentheses).
I tried to descend into 'src/python/api' by typing 'cd s<Tab>', later with src completed, 'cd src/py<Tab>'.
Here are the results: using the value 'tag-order local-directories named-directories' helped with completing src/, the directory name was completed immediately upon hitting Tab. The second dir (python) was not completed on the first Tab press. Typing another Tab did *not* produce a list of suggestions.
Here is the result of 'sr<ctrl+x h>' and 'src/py<ctrl+x h>'.
% cd sr<ctrl+x h>
tags in context :completion::complete:cd::
local-directories named-directories (_cd)
users named-directories directory-stack (_tilde _cd)
users (_users _tilde _cd)
% cd src/py<ctrl+x h>
tags in context :completion::complete:cd::
named-directories (_cd)
local-directories (_cd)
% cd src/python/<ctrl+x h>
(no results)
Do you think that there is anything suspicious? Personally I wonder why there are duplicated entries in the first case and why are the tags listed in a reversed order in the second case. And yes, the empty result list in the last case.
Peter