How to make light affect selective objects?

I have this scene where golden-ish fluid is traveling through pipes and there’s an obstacle that has coal like material.


There are two lights:

I want the big - Light 1 - Golden to affect the fluid and ignore the black obstacle. And the small light 2 - Normal/Dark to affect the obstacle and ignore the fluid.
Because right now, the black color of the obstacle becomes green due to the yellow light (ref - first image).

How to achieve this?

This is a feature called light linking.
You have to either wait for Blender 3.6 which will be released on the 27th of june or you have to use the 3.6 Beta which can be downloaded at blender.org: