Grouping layers that have been added with "add layer to map"

Hello everyone,

we're using the activity "add layer to map" to add layers to our webmap on application startup:

While adding layers at a certain position using “index” is already very helpful, it would be even better if we somehow could add these layers to already existing groups, or even create new layer groups to add those layers to. 

Does anyone know of a way to do this?