In the Tab Menu webpart, is there a way of setting the 'Content > Path' property to display only the sub items of the parent document which the visitor is in?

For example:
/% - will show all level 1 pages
/%/% will show all level 2 pages (across the whole site)
/documents/% - will show all level 2 pages within the documents folder

I need something that will show just 'the current' document's items, for example:
/{%parent_document%}/%