Is there a way to get the folders in "devices" listed from the webservice?

Is there a way to get the (custom) folders in "devices" listed from the webservice? And how to get info about the contents of the folders (what devices are in it..)

ListCustomPatchGroups  returns all custom groups, but does not specify the "type" of group (if it is created in Ditstribution Packages"or "Devices" or elsewhere.