Combine flows from load balanced interfaces?

I have a main layer 3 switch that has two routes out to two separate routers that it load balances between. Those two routers then connect to a main router and then out to the world. Is there a way to see combined graphs for traffic in and out of the interfaces that are load balanced between?

I've created some IP groups for known IP addresses that balance between the two connections, so I can see summaries for those regardless of what interface it's using. But I'd like to see all of the summaries and pretty graphs for all traffic IN and OUT of those two interfaces combined. Any way?

Thanks.

---John Holmes...