There's no way to tell for sure who 'them' are from just this title. It could be any group of people, like a group of friends, coworkers, or even a sports team.
I'm not sure specifically which 'them on prime' story you're referring to. There could be many shows or events with that kind of title. It might be about a group of people ('them') in a prime or important situation, perhaps in a business context, or it could be a story about a group's experience on a platform like Amazon Prime.
If 'them prime' is a relatively unknown or new production, it might be difficult to determine off - hand what it is based on. You could try searching for it in specialized entertainment databases or forums where fans might discuss its origin if it is based on a true story.
Since I don't have a clear understanding of what 'them prime' is, I can't give examples of ones based on a true story. It could be a brand - new creation that hasn't been widely publicized or something very niche. You might need to clarify what 'them prime' actually is to get relevant examples.
Prime Hunters isn't a true story. Usually, such names indicate works of fiction that are made up for entertainment purposes rather than being based on real events.