toc-tabbed-internal-nav" from Table-of-Contents Macros? With your "index" tiddler being the only one tagged with the tag used for this toc, it may achieve something not too far from what you want?toc-tabbed-internal-nav" macro, but my "index" tiddler of links is split into categories by field values, which would then required a unique tag for tiddlers in each category, removing the fun (and convenience) of just tagging them all "my tag" and then using your edit template method to choose the category (and other fields) from a drop-down select widget.
If it's possible (?) to add a tiddler tag automatically based on a field value, then I could modify the edit template to do that. So I tag a tiddler with "my tag" and somehow depending on the value I choose/define for the "category" field, it adds a tag named !!category. I think this would also require a tiddler of the same name as the category value to exist for the "toc-tabbed-internal-nav" macro to work .
Another drawback of the "toc-tabbed-internal-nav" macro is that in the "index" tiddler I was going to have a two column table with column1=link and column2=!!summary field. If this data was concatenated and used as a "caption" field the toc menu items would be too long.
What I really wanted was for each row of the "index" table to be a link itself and reveal the contents of the tiddler when clicked. To look a bit like Tobias Beer's Slidr macro for TWC http://tobibeer.tiddlyspace.com/#Slidr
but with the content of the tiddler being revealed. I really like the way the whole row is a link, rather than having a button; very pretty tb! can you do this for TW5?
All the best, Bob
\define modTabs()
<<tabs "[[Select Tiddler]][[$(SelectedTab)$]]">>
\end
<$set name=SelectedTab value={{$:/state/Special Tabs Select State!!selected_tab}}>
<<modTabs>>
</$set>
<$select tiddler='$:/state/Special Tabs Select State' field=selected_tab>
<$list filter='[tag[HelloThere]]'>
<option><<currentTiddler>></option>
</$list>
</$select><$navigator story="MySubStoryList!!list" history="MySubHistoryList"><$list filter="[list[MySubStoryList!!list]]" history="MySubHistoryList">
! <$view field="title"/>---
<$transclude mode="block"/></$list></$navigator><ul>
<$list filter="[tag[Concepts]]">
<li><$button set="MySubStoryList!!list" setTo=<<currentTiddler>> class="tc-btn-invisible">
<$view field="title"/>
</$button></li>
</$list>
</ul><<tabs "Index Substory" "Index" "$:/state/tab1">>