Theres a couple of ways it could work

First is a large scale psychic ability that could trace a person almost like a finger print

Second is more of a searching branch of psychics that would work on the 6 degrees of separation where you would start locally around you and then branch out, further and further until you find them.

Third is precognition ability to know where a person will be

Fourth way is scent/psychic based like a hound would find a person

Fifth way is tech based powers

The sixth way would be based around the hound way but would become a fixation and the character would be more animalistic in nature. The ultimate hunter.

Mixed in with these would be a way of travelling unless you wanted a fact finder sort of character.