You can use bind in order to maintain a reference to your layer. For example:
l_FeatureLayer.on("edits", otRilievi_Object.rilievi_edits_complete.bind(otRilievi_Object, l_FeatureLayer));
...and elsewhere...
this.rilievi_edits_complete = function(target, p_Features) {
//target is now a reference to the layer being edited
};