In the following image, the polygon without filling and the polygon with the red filling are two different layers. In my atlas I would like that only those red Polygons are represented that are inside the polygons with no filling.
The atlas is iterating over the polygons with no filling.

IDin red polygons and create a rule symbology with the@atlas_featureid. – J. Monticolo Dec 03 '19 at 08:51