From the HTML5 spec:
The section
element represents a generic document or application section. A section, in this context, is a thematic grouping of content, typically with a header and possibly a footer.
and
The article
element represents an independent section of a document, page, or site. This could be a forum post, a magazine or newspaper article, a blog entry, a user-submitted comment, or any other independent item of content.
So I would say both section
and article
elements can contain the other element, if appropriate. I think your diagram makes sense, apart from the nested section elements:
The section element is not a generic container element. When an element is needed for styling purposes or as a convenience for scripting, authors are encouraged to use the div element instead. A general rule is that the section element is appropriate only if the element's contents would be listed explicitly in the document's outline.
Maybe use a <div>
for the outer one?