How to select which NavMeshSurface my NavMeshAgents use?

In Unity, I have decided to use multiple NavMeshSurfaces to represent different floors in my game.

Is there a way to select which NavMeshSurfaces my Agents can use?

Different Agents will be at different floors at different times, so I cannot disable any surfaces. I will also be creating the NavMeshSurfaces during runtime, so I cannot create any new agent types.

If you have a suggestion, I will be grateful for a reply.