In Character Configuration, there is a Hotbar section. There is a tab called "Sharing". You can choose which hotbars are shared among all jobs. The "shared hotbars" are a separate set of hotbars, so if you disable this you will have to place the actions again on each individual job.

You can also copy the hotbar from one job to another.

To copy hotbar #1 from paladin to your current job do /hotbar copy PLD 1 current 1
To copy the shared hotbar to your current job do /hotbar copy shared 1 current 1
To copy gladiator hotbar #1 to paladin hotbar #1 do /hotbar copy GLA 1 PLD 1