Adding HingeJoints to Script fields in Inspector

I have declared public variables in my script for a bunch of HingeJoints, and it's created empty fields in the inspector like it should, where I could drag those HingeJoints from the scene. However, one of my GameObjects has four HingeJoints on it, and it seems I can't figure out how to drag the individual HingeJoints I want onto the proper four fields so that my script refers to the right joint with each variable in the script. How do I achieve this?