Trying to put two sets of postprocessing effects on two scenes

I have two scenes, one scene that’s like a background ( only particles) and the second scene in which there is a 3d model. I want the background to have one set of postprocessing effects and the foreground to only have filmpass. I know how to use a composer for the background, but when I try to set it up for the foreground it doesnt work. Now, I only have
…composer.render(delta); renderer.clearDepth(); renderer.render(scene2, camera);…
which for now puts effects on the background and the foreground is just rendered normally. I tried using two composers but I can’t get it to work. Is there an example of this anywhere? I’m not talking about two different viewports.

Thanks in advance!