There are two ways to go about doing this.
The first method assumes that all the items listed above will result
in rendered pages that the user can navigate to. In this case, you
would first find the appropriate "Element" page by name and then
render it in the parent page ...
<% page = @pages.find( :title => 'Element 1.1' ) %>
<%= page.render %>
The above snippet would appear in the text file for the "Element 1"
page. Something similar would appear in the "Page A" page. The clever
programmer would put the desired page names in an array, loop over the
array and find the pages, and then render each page.
The second method assumes that on "Page A" should end up as a rendered
page that the user can navigate to. In this case, all the "Element"
pages would exist as partials in the content folder. A partial is any
page in the content folder whose filename starts with and underscore _.
In "Page A" then, you would have a snippet of code like this ...
<%= render_partial('element_1') %>
This will find the partial file "_element_1.txt" in the content folder
and render it's contents into "Page A". In the _element_1.txt file,
you would have something like this ...
<%= render_partial('element_1_1') %>
<%= render_partial('element_1_2') %>
Again, you could put the partial names in an array and iterate a block.
Hope this helps.
Blessings,
TwP