The button to the right of the name box is to switch between "level up mode" (which means you pick a power, place slots, pick a power, place slots, etc etc etc, until you're done - like you do when you level up in game) and "dynamic mode" (which allows you to pick powers and place slots independently of each other).
The button to the right of that switches between "only allow me to pick powers (placing slots is disabled)" and "allow me to pick powers and place slots".