[quote=Kael Taiyou]
Let's see if i can do this[hider][hider2]Hi![/hider2][/hider]Fail
[/quote]

You need to put = and a title to the hiders.

Like, [hider=something
[hider2=something else
Derp
[/hider2
[/hider

[hider=something]Derp
[hider2=something else]
derp[/hider2][/hider]