Comment # 6 on bug 1208645 from Ra���l Osuna

(In reply to Stefan Dirsch from comment #4)
> Now you can play with
> 
>   xrandr --output <output-name> <--left-of |  --above   ...> <output-name>
> 
> See 'man xrandr'.

raul@laptop:~> $ xrandr --output DP-3.1 --left-of DP-3.2
raul@laptop:~> $ xrandr --output DP-3.3 --left-of DP-3.1
raul@laptop:~> $ xrandr --output DP-3.2 --left-of DP-3.1

After each of those commands, the working external screen was being moved, but
the other two external ones did never turn on.