I don't think 'Full Circle' is a true story. Usually, works like this are crafted by authors to tell a compelling tale that might draw from various sources but not be strictly based on reality.
The 'full circle true story' could be any number of things. It could be a historical event that had a cycle of development. For example, a particular culture that was once dominant in a region, lost its influence over time, and then through the rediscovery of its heritage and values, regained some of its former glory. It could also be a story of a family heirloom that was lost, passed through different hands, and then found its way back to the original family.
Sure. There's the story of the prodigal son in the Bible. He left his family with his share of the inheritance, squandered it all, and was left in a desperate situation. But then he decided to return home, and his father welcomed him back with open arms. So his journey away from home and then back again is like a full circle, and it's based on a religiously - considered true story.
One example could be 'The Blind Side'. The story comes full circle as it starts with a young man in a difficult situation, and through the kindness of a family, he not only improves his life but also gives back to the family and community. It's based on a true story, which makes it even more impactful.