SOLVED In case anyone else has this problem, here's where I found what I needed. File: /nodebb/src/controllers/helpers.js Methods: buildCategoryBreadcrumbs and buildBreadcrumbs Editing those allowed me to get the behavior I was looking for. Although, I would be curious to know if there is a better way to do this without changing the source code.

SOLVED Just in case anyone else runs into a similar problem, I was looking at the wrong api urls to get what I needed. I needed to be getting JSON from the topic data, rather than category or post. Most everything is working now.