Spotted this on YT. American driver, presumably left h ooker, reversing a B-douible on blind side. Fair play to him especially with comparatively short trailers thus more difficult.
To those who wonder how, the principle is simple. Work out where you want the 2nd trailer to go, then think how you would achieve it if it was a rigid. Then work out how you would achieve that and point the arse of the first trailer accordingly. Simple., but nevertheless a skill required and mastered.
That looks like a Canadian configuration, Spardo. Impressive skills there, kudos.
My advice to new B-double drivers is smooth, gentle steering input and try to avoid jack-knifing the trailers. This bloke was obviously in a situation where he had no other choice. I generally find once the two trailers have gotten to greater than a 45⁰ angle, it’s too late to chase the B, necessitating a shunt.
Yes, he just had one little ‘straightener’ right towards the end. I would have been interested to see more, and where he was needing to put it.
Perhaps it all went pear shaped especially if it might have been a long straight run to wherever. 
Are you suggesting he backed into the wrong driveway? 