On controller you can hold R1 and press the associated face button or d-pad direction to change between your 8 cross hotbars. Normally I think the first two or three are job-specific, so you don't need to worry about losing them when you change jobs. Once you have something on the second hotbar you can tap R1 to toggle between your first and second hotbar. There's also a feature where you can hold both triggers and have it display half of your second or third hotbars, and you can set L1 first then R1 to be different from R1 then L1.