You can find this filter through
→ → .It generates a blind effect with horizontal or vertical battens. You can lift or close these battens, but not lift the whole blind up.
All your setting changes will appear in the Preview without affecting the image until you click on OK.
Allows you to decide whether battens will be horizontal or vertical.
The batten color is that of the Toolbox Background. To be able to use the Transparent option, your image must have an Alpha channel.
Displacement: Slider and input box allow to wide battens giving the impression they are closing, or to narrow them, giving the impression they are opening.
Num Segments: It's the number of battens. Note that Displacement must be about 50 to have all gradations of this number.