If you need to write your own render pipeline and want to get rendered geoemtry from agent, you can directly use below command:

Python command: 

McdGetAgentGeoList(<agent number>)

example:

McdGetAgentGeoList(10), it wil return 10 groups of geometry names from agent 1 to 10, and split by "-" sign.

Please refer the below image:

And these geometries are all based on below rules:

1. Get randomize geometry by randomize rule (Simple Geometry Randomization)
2. Get LOD filtered geometry (Level of Details Setup)