State condition based on attributes - for light

Hi,
I have I guess a pretty simple task to do - create a state condition based on the attribute of the light dimmer. If I look in home assistant in dev console, it has the following attributes:

supported_color_modes: brightness
color_mode: brightness
brightness: 64
friendly_name: Flush Dimmer 0-10V
supported_features: 32

I want to work with brightness - I tried to put it as json in state node but no luck (not defined). Can you please help me how to do that (i.e. define that if the brightness is above something, do action)?

Thanks a lot!!