Bachelor Thesis supervisor in a CV?
You can certainly add them to your CV. There's no general rule on how to write CVs so it's more or less personal preference. For an academic CV, teaching might be an important point, so I like to include "teaching experience" as a section but I prefer only mentioning "supervision of 5 bachelor theses and 2 diploma theses", otherwise it would get quite long.

In the end: if it makes sense and the information provided shows your qualification for the job then you should include it.