In short, no, but it's how BEACN Mix was designed.
For simplicity, we allow you to drag and drop several programs to one knob. In most cases, like games, music programs, video players, etc. you'll only be listening to or using one of each type of program at a time.
If you do have multiple programs on a knob and you're using them both at the same time, BEACN Mix will adjust both audio levels simultaneously.
Try renaming the four knobs for use as a group. We like Games, Music, Chat, and System as a starting point, but you can use anything you like.