Mapping between Global User attributes and attributes of an account on an endpoint is described in CA Identity Management and Governance Connectors Guide, however questions are still been asked.
This article provides some explanation.
Component : IdentityMinder(Identity Manager)
[Question] I can see are lot of gaps between a Global User details and an account on an endpoints details, from which a global user was created. How can I synchronize all the data on endpoint account and on a Global User?
[Answer] By default for most endpoints only a minimal subset of account attributes is mapped to global user attributes.
This is done to improve performance during endpoint exploration.
If you need to populate Global User attributes from account attributes, you need to define additional attribute mappings. Follow these steps to set up attribute mapping (using IM User console):