How to eliminate small polygons to adjacent large polygon the same commune?

@hoa_le​ The LeftRightSpatialCalculator might work if the red line in the image is a boundary or line you can use. If the red line is a boundary, then SpatialRelator might be what you need.

I don't have access to FME desktop right now, so the names/parameters might not be exactly right.

If you don't already have the commune as an attribute on your polygons use the SpatialFilter, SpatialRelator or Clipper to transfer that (merge attributes).

If you don't already have a unique ID (UID) use the counter to create one.

AreaCalculator on your polygons

Tester to separate your silver polygons (_area <0.01) from the rest of the layer.

SpatialRelator with the sliver polygons as the requestor and the rest of the polygons as the supplier. Group by Commune. in the Generate list, include UID and _area.

ListSorter on _relationship{}._area descending

ListIndexer to promote index 0 to regular attributes making sure that the UID from the List overrides the UID from the sliver.

Dissolver with the sliver polygons (ListIndexer output) and rest of polygons (tester output) group by UID.