Hi,
Currently we can only choose an existing post from the dynamic preview search box as a template preview source.
The issue with this system is that most of the time, categories, tags, or taxonomy archives & terms are not associated to actual posts. We just use their slug to reference them (in a main menu for instance), and WP does the job to retrieve the right query. Like domain.ext/cpt_archive_slug/ or domain.ext/post_category_term_slug/.
So, when working with generic archive templates, like index.php or archive.php, we can’t select the right source for preview, and we have to work blindly.
I think we need a way to choose categories / tags / taxonomy archives & terms as preview source.
Maybe the search box could be modified to accept free manual text surrounding by slashes like /slug/, so that the right query could be applied, or maybe the search box could detect archives and terms names and add corresponding entries to the dropdown?