If you mean the cross class actions, here's the command you are looking for. Remember though that toggling them on and of can incur cooldowns and I'm not sure if switching them is possible in mid craft anyway.

ALIASES:
　/additionalaction, /aaction
USAGE:
　/aaction "action" [subcommand]

→Set the specified action as an additional action for your current class.

>>Subcommands:
　on Set additional action.
　off Remove additional action.

Toggle between on and off when no subcommand is specified.