How to split feature with multipolygon geometry into multiple features with single polygon geometries in GEE

Question

I want to isolate the geometry of the ecoregion intersecting my ROI. However, using .filterBounds() produces a multipolygon with segments that do not intersect my ROI. Instead, I only want the polygon that does intersect with my ROI.

So far I have managed to produce a list of individual polygons extracted from a single ee.Feature with multipolygon geometry, but what I want is actually a ee.FeatureCollection where each feature is a single polygon but keeps the properties of the original feature. This is what I have so far:

var ecoregions = ee.FeatureCollection('RESOLVE/ECOREGIONS/2017');

var filteredEcoregion = ecoregions.filterBounds(ROI);
print('filteredEcoregion',filteredEcoregion);
Map.addLayer(filteredEcoregion,{},'Filtered ecoregion');

var multipoly2poly = function(multipoly){
    var size = multipoly.coordinates().size();
    var polylist = ee.List.sequence(0, size.add(-1), 1)
      .map(function(listelem){
          return ee.Geometry.Polygon(multipoly.coordinates().get(listelem));
      });
    return polylist;
};

var filteredEcoregion2 = multipoly2poly(filteredEcoregion.first().geometry());
print('filteredEcoregion2',filteredEcoregion2);

Link to code: https://code.earthengine.google.com/edf61201854677a12d3420248b1a138f

Answer 1

Actually it just was a matter of adjusting the function I was using :

var ecoregions = ee.FeatureCollection('RESOLVE/ECOREGIONS/2017');

var filteredEcoregion = ecoregions.filterBounds(ROI);
print('filteredEcoregion',filteredEcoregion);
Map.addLayer(filteredEcoregion,{},'Filtered ecoregion');

var multipoly2poly = function(feature){
    var multipoly = feature.geometry();
    var size = multipoly.coordinates().size();
    var polylist = ee.List.sequence(0, size.add(-1), 1)
      .map(function(listelem){
          return ee.Feature(feature)
            .setGeometry(ee.Geometry.Polygon(multipoly.coordinates().get(listelem)));
      });
    return polylist;
};

var filteredEcoregion2 = ee.FeatureCollection(multipoly2poly(filteredEcoregion.first()));
print('filteredEcoregion2',filteredEcoregion2);

var filteredEcoregion3 = filteredEcoregion2.filterBounds(ROI)
Map.addLayer(filteredEcoregion3,{color:'blue'},'filteredEcoregion3')