Anita, are you asking about a transcription using Nemeth Code within a UEB context? If so, then any mathematical symbols must be within Nemeth Code switch indicators, and a dot locator (which is a UEB tool) would not be appropriate or necessary.
If you're asking about a transcription using ONLY UEB (and no Nemeth Code), then you still probably do not need any dot locator symbols. Though, it's possible you could need a dot locator for use in front of "a braille symbol which has only lower dots and which is isolated from other text" – see Rules of UEB section 3.14.1. (The dot locator for mention is designed for symbols lists, transcriber's notes and publications about braille; see Rules of UEB section 3.13.1.)
Thank you for the question!