The way Source Settings works in Premiere Pro is to modify all instances of the same clips on all timelines, so any change will affect all instance of the same .braw imported. This is only an issue on Premiere Pro because on After Effects you have the Layer Settings filter that is applying the RAW parameters on the current layer and not the source. : "Set New Source". You just need to select a clip and click on the button in the BRAW Studio Panel !More information and youtube tutorial here !If you want to do it manually, you have 2 choices : 1. Import the same footage many times (as much as you need different color corrections on this footage) and change each Source Settings 2. Or Use the "SubClip" feature, see this article :

Import your braw footage
In the "Source Monitor" panel, choose the bounds to your first "Sub Clip"
Right click in the Project panel in your footage and select "Make Subclip"
After this : you will have a new source in the project (the subclip) with different RAW Parameters.