Here is my hierarchy of Page Menu items

-Newsletters
---2006
-----June 2006 Edition
------Articles
---------Article1
---------Article2
------Headlines
---------Headline1
---------Headline2
---------Headline3

I have a CMSDataList with a blank SelectNodePath that retrieves headlines. When placed on a page template for Headilnes, this works fine. However, it does not work when placed on a page template for Articles. My expectation was that it will automatically read the alias path of an article and show a list of headlines for the corresponding edition (2006).

Am I missing something? How to retrieve the list of headlines on article pages?

Related questions are:
1. Is it better to create document templates (EditionContainer, ArticleContainer, HeadlineContainer) or Page Menu items are fine? Any advantages/purposes of one approach over other?

2. When I add another edition (July 2006) and visit the headline and article pages, they come up blank. So, /Newsletters/2006/June-2006.aspx works fine but /Newsletters/2006/July-2006.aspx doesn't work. Any ideas?

I am hoping this question will enlighten the concept of aliaspath, transformations, and user-friendly urls used in KenticoCMS.