This morning I was getting in some archery practice before the day gets too hot (I managed to knock out just over 100 ends without feeling achy, which is good progress in terms of conditioning) however I struggled with concentration ... there were many things to distract me, mostly noise but also being attacked by mosquitos and a little frustration with part of my technique that I need to work on.
I took my time to breathe and try to focus, but with someone splitting bricks by hand nearby it still cut into my head.
You may want to consider looking at some of the literature by Larry Wise. He has done some significant research, writing and coaching on just this topic on the mental focus aspects of archery. Take a look at: https://larrywise.com/planning-to-peak-in-archery-page/
He is also currently doing some cool research and experiments to better understand Quiet Eye theory that will fold in to some of what he talks about there. Probably another publication coming out about that and eventually.