[Zope] template / context question

[Erik Myllymaki]

I am trying to separate out small bits of HTML that are used on many 
pages of a site.

In one case I use a secondary navigation on some pages in the right 
column that is supposed to look in the containing folder's sub-folders 
and list the Page Templates that is finds there.

I create a folder called /templates/widgets and within there I have a 
Page Template called template-lister.

<h2><strong>Quick Links</strong></h2>
<ul tal:define="ztu modules/ZTUtils;
raw python:context.objectValues('Folder');
location_folder_list python:ztu.LazyFilter(raw, skip='View')">

     <li tal:repeat="location_folder location_folder_list">
     <a href="" tal:attributes="href location_folder/absolute_url"
        tal:content="location_folder/title">Location Title</a>

         <span tal:define="raw 
python:location_folder.objectValues('Folder');
                                           office_folder_list 
python:ztu.LazyFilter(raw, skip='View')">
         <span tal:repeat="office_folder office_folder_list">
              <span tal:content="office_folder/title" >title</span>

              <ul tal:define="raw 
python:office_folder.objectValues('Page Template');
                                     posting_list 
python:ztu.LazyFilter(raw, skip='View')">
                <li tal:repeat="posting posting_list"
                         tal:condition="posting_list">
                    <a href="" tal:attributes="href posting/absolute_url"
                          tal:content="posting/title">Posting Title</a>
                </li>
                <li    tal:condition="not: posting_list">
                   No Postings at this time
                </li>
             </ul>
         </span>
         </span>
     </li>
</ul>


If I put this code directly in each Page Template that uses it, it works 
fine, but when removed from each Page Template and called like so:

<span tal:content="structure context/templates/widgets/template-lister" 
tal:omit-tag="" />

it uses the context of the "/templates/widgets" folder and does not work.

Because this bit of TAL is used on many pages and the style of it 
changes often, I really want to pull it out into one place for easy 
updating.

I know I am missing something elemental here ...

Thanks for any advice.