On my controller settings I have my first bar as usual, then my second bar uses the extended cross hotbar L2>R2 for left side and R2>L2 for right side. If I need a 3rd hotbar it is fine as well.

One tip I would have is learn to cycle hotbars with holding R1 then pressing the corresponding face button. I got used to it and can now easily cycle through all of my hotbars easily without having to press R1 a bunch of times.
Want to go to the 3rd? R1+X, use the ability, then just R1+triangle back to first hotbar. Dont have to press R1 multiple times to get through to different hotbars