What I do is click on the component I want to do CAM on and select "Isolate" (only available on Model view). Then I switch to CAM view and make my setup (I think it chooses just that component by default) and do my CAM stuff. Repeat as necessary. There's also an option to select the components you want included in your setup, but I rarely want to see anything other than the part I'm CAMming at the moment.