This is how I get feature info from a **group layer** when clicking on the map (using WMS `getFeatureInfo`):

```javascript
let view = this.map.getView()
let viewResolution = view.getResolution();
var source = this.groupLayer.getSource();

var url = source.getGetFeatureInfoUrl(
  this.map.getEventCoordinate(event), 
  viewResolution, 
  view.getProjection(), 
  {'INFO_FORMAT': 'application/json'}
);

this.expedientesService.getExpsClick(url).subscribe(exps => {
  console.log(exps)
})
```

**The problem:** This request is returning only one feature even if there are more than one on that clicked point.

The url generated by `getGetFeatureInfoUrl` has the following format:

```
http://foo?
SERVICE=WMS&
VERSION=1.3.0&
REQUEST=GetFeatureInfo&
FORMAT=image%2Fpng&
TRANSPARENT=true&
QUERY_LAYERS=groupLayer&
LAYERS=groupLayer&
INFO_FORMAT=application%2Fjson&
I=50&
J=50&
CRS=EPSG%3Axyz&
STYLES=&
WIDTH=101&
HEIGHT=101&
BBOX=570384.8749920629%2C4722144.92875535%2C570386.7576818952%2C4722146.811445182
```

(I think I and J are always 50, don't know why)

> [As seen here][1] If there is more than one feature at the point then
> it may return information about all the features (up to
> `featureCount`) that are there.

 Any idea of what is wrong here?

I have an auxiliar layer containing all the features, and when making a WFS `GetFeature` request, multiple features are returned.


  [1]: https://gis.stackexchange.com/a/189411/138448