This question has been answered by multiple community members. See the first response.
[[$head]] [[$header]] [[*content]] [[$footer]]
[[$myTemplate? &contentchunk=`baseContent`]]
[[$myTemplate? &contentchunk=`specialContent`]]
[[$[[+contentchunk]]]]
<div id="content"> [[*content]] </div>
The usual way, to have different TVs for different Resources, is with different Templates.
Another way is, to have the template code in a file and let all templates be static and point to the same file.