Try filtering to exclude the UID of the sprite you don't want chosen.
Could you give some kind of example pseudo code? I get where you're going but am unable to replicate it.
I'd be happy to see this workaround, but I don't think it negates the initial suggestion. If you ask a person where the nearest human is, they will not point to themselves. It's really unintuitive and not useful for an object to find itself with this kind of function.