If you leap tall buildings in a single bound for the Des Moines branch of your corporation, then your Metropolis counterpart might be Superman. That means you and Superman do similar jobs, but in different locations.
The noun counterpart comes from the French word countre part, meaning “duplicate of a legal document.” In legal circles counterpart still means "a duplicate document," but today it is more likely to describe people. Counterparts aren't duplicates, of course, but they have similar skills and responsibilities. If you play soccer, your counterpart is the player on the other team who plays the same position.