You can either put key frames on each audio clip, then mark an in and an out between all the clips you want to adjust. Then you can change all clips between your markers. I’m not in edit atm, you may need to hold down alt also.
I usually make the tracks big when using audio key frames.
The other way is to mark your in and out on the tracks you want to adjust, say 3&4. Then in the audio mixer, make sure you have the gang linked turned on for 3&4, thats the green symbol above the channel fader that allows you to symaltaniusly move multiple faders. Then turn up/down volume to required amount. You then go to pull down menu on mixer and select ‘adjust level between in and out’ again not entirely sure of wording here. This will adjust all levels between markers to your mixer level.