Filter layers on layer group with OpenLayers and GeoServer?

Question

I have a layer group with multiple layers as following

In Angular I created an OpenLayers map adding the group layer like this:

this.capaPropia =
new ImageLayer({
  source: new ImageWMS({
    url: environment.baseUrl + 'handlerGeoserver.ashx',
    params: {LAYERS: 'v_expedientesAgrupados'},
    projection: proyeccion
  })
});

In my app I have 4 checkboxes, one for each layer. I need to display only the layers of the group layer that are checked.

Is it possible to filter layers from a group layer on GeoServer (with cql_filter or similar)? If so, can this be done with OpenLayers?

Answer 1

That is not how layergroups work, they are a single indivisible layer as far as the client is concerned so there is no way to know that there are 4 layers inside it let alone turn them on or off.

You need to request the 4 layers separately from the server to allow the client to turn them on and off. See this question for example code.