Deathrun Zones having 1 Player have top 3.

So I know it's possible to do but I have no idea how, I don't see any existing code for it in the gamemode. I'm using Arizard's Deathrun as my gamemode and the zones that come with it. My problem is that one player can own all three parts of the leaderboard and I have no clue how to make it so players only have 1 record. Any help would be appreciated!