Looper Effects A/B - A+B

[JackSkellington]

Hello everybody.
I can't find any diagram or schematic for a looper effect with two loops, A and B, with three footswitches: Bypass, A/B, A+B.
I tried to draw it by myself, but I'm in difficulty.
I hope the configuration is clear. It should be like this:
https://www.loop-master.com/cleandirtychannel-switcher153wcombinable-loops-p-274.html
But this has the channel amp switching, too, at the same time when you pass from A to B, that I don't care.

Like this:
https://www.brightonion.co.uk/aby-dual-looper/

Thanks!