Sorry about the late reply but I played frisbee golf and drank some before making the pic.
Black is the actuator
Green is the arm
Yellow is the sliding door
Red is the pivot point
By adjusting the pivot point the amount of movement will change more or less the top half shows it moving more the lover half moves less.
By adding this to the bar.
With the yellow bar being the same as above, and the red being the pivoting attachment point to the bar will allow the blue slats to open. (The blue slats will need a second mounting point in the middle of at the end that will be stationary that is dependent on what you use for the slats.)