If you mean how to put that action on your hotar, Canadane's reply has your answer. If you mean a way to make your job's regular actions work that way, it's not intended. There's a work-around that sort of makes it possible, but with enough downsides that it's not recommended.

(The work-around involves macros, and setting up multiple versions of your hotbar stored on extra hotbars you're not using. The macros perform an action and then swap your main hotbar to the next one where a similar macro with the following skill has the same hotbar slot. The biggest problem with it is that you can't queue up actions in advance if they're in a macro, like you can if they're activated directly, so it slows down your combat.)