How to change loudness adjustments professionally?

Thanks, I’ve already thought, that that would be a possibility, but I wasn’t able to affect another track except the first one. So how to affect the other tracks? If I change the bus number maybe to 2 or 3 and so on, there only can be affected the first track furthermore. How do you accpmplish to affect tracks, which are below the first one? I’m really courious, thanks again!