Hello, in what is now known as map viewer classic then you were able to add a map image service with a URL, remove some of the layers from the layer group that the respective service becomes when added to a map, save that new group setup under a name. Add the same service again, make some other changes and save that setting as something else and so forth...
Thus you were able to create several groups from one map image service without loosing your symbology nor needing to rely on feature services.
I however do not see that this is possible in the new map viewer, you can only save groups if they include feature layers or groups that are created with the group function in the new viewer.
Or am I missing something and you can actually to the same workflow as from before in classic map viewer in the new one?