I have done a lot of sling work with the Bell 222.
The mirror is located at the standard location viewed through the chin bubble. Its adjustable up/down from the cockpit.
I liked slinging with the B222, very restricted visibility, good ground crew with radio was great help. But you get used to it so unaided slinging was quite fun too.
I needed to get used to having the cargo hook 3 meters behind me, even further 30cm back in the B430.