Question about keybinds help

please guys please i just wanna know how i see people in youtube
and guides and when i watch them i clearly can see
ONE keybind for 2 different spells


how is it possible?
when i try to keybind middle click to be right click
its obviously not overlap and disable each other
so how i see people with this keybinds

The image website you use is blocked in my region so I can't see exactly what it looks like.

At a guess though the are using some combination key with right click for one of the skills.

You can set Ctrl-Rclick, ALT-Rclick and Shift-Rclick for any skill without effecting your standard Rclick skill.