I'm assuming your controller works the same as PS4, with two sets of trigger buttons - one that switches hotbars and one that you hold down to activate them.

There should be a setting in one of the config menus that turns on expanded hotbars - one for accessing a second row by pressing the other trigger, and a different setting to access a third hotbar by double-tapping the trigger.

Additionally if you hold down the "switch hotbars" button and press one of the attack/directional buttons, it should let you switch to a different specific hotbar that way.