G'day,
When the relink plugin is installed, that adds a "Relink References" tab to a tiddlers "information".
That shows "The following tiddlers contain fields, links, macros, transclusions, or widgets referencing this one."
Relink might provide a way for you to get what you're looking for.
Give it a spin.
Install the relink plugin, then add the following line in the text of Tiddler B:
{{||$:/plugins/flibbles/relink/ui/TiddlerInfo/References}}