Follow-up from: http://support.statamic.com/discussions/general-questions-best-practices/17025-get-pagesnext-and-pagesprevious-from-current-url

I have a content tree that looks like this for a documentation site:

_content
../html
../../1-styleguide.md
../../2-semantics.md
../../3-conventions.md
../../page.md
../js
../css

If I'm on the "semantics" page I'd like to follow the content with a next/previous link to styleguide/conventions. I can hardcode folder attribute of the pages:next tag like this:

{{ pages:next folder="html" }}
    {{ if !no_results }}
        Next up: <a href="{{ url }}">{{ title }}</a>
    {{ endif }}
{{ /pages:next }}

But obviously it can't be hardcoded. The documentation suggests there's a "current" parameter but I can't find an example or way to use it, and there's no global tag to get the parent URL.

See: http://statamic.com/learn/documentation/tags/pages