Important points regarding Services roll-up:
There are three service types:
1. Global Service
2. Local Service
3. Category (not really a service, but more of a container).
* The only 1 of the above 3 that can be contained into another service is the Global Service
* You can see what is Global Services: Admin Console | Services | Object Groups | Global Services row item | Test icon next to Global Services row item --- this will list out all Global Services -- these can be "rolled-up" or "contained" within another service (Global, Local or Category).
* How to contain a Global Service into another Service/Category:
Admin Console | Services | Service Builder | choose Service/Category Row - 'Add' | Add Component | From drop down:Global Services | pick your Global Service