Icinga Director: No Variables in Field Tab for Command

I have a little problem with a command that I added in director.
It need some variables in the command which I defined unter the arguments aab in the command:

" Argument Name: -H
Value : %my_hostname%
and not much else, I add that and go over to the Fields tab to look if it is there and there is nothing.
I restarted the whole server just in case and deployed the config but nothing shows up.

Am I missing something or is this a weird bug?