In the version I am running, 2006-03-09b, writing the following in a page
[[..|name]]
defines a link to the page associated to the directory in which the page is sitting, if any.
By the way why not map the directory to a page containing `ls -lt' when there is no page associated to the directory ?
I'd also prefer to have the page for directory 'dir', sitting inside 'dir', and being called 'index' by default, instead of having that page sitting one step above 'dir'.