At present it is possible to use configuration framework to describe service config options. One of attributes which can be set for configurable service is factory which implies "multiplicity" of these.
Looking at the sources this attribute is currently used in very few places with fairly strange attitude. The configuration part of framework is intended to cover OSGi ConfigurationAdmin and its behavior with ManagedService and ManagedServiceFactory. Yet I have impression that current logic fails to detect managed service factories and their sub-configurations.
I found this while trying to make UI render properly multiple service coming from same factory but different configurations.