Rollershutter currently can only be opened and closed. It does not support additional attributes necessary for blinds, e.g. tilt.
One option would be to extend the rollershutter entity, another option would be adding a new Blinds entity with additional functionalities.
A blind should have at least the following parameters and functionalities:
-
position (0-100%)
-
angle (0-100%)
-
up/down
-
tilt up/down