There are two ways to pull the work items from queues. The first approach is: when a user User1 logs in from the specified user-realm (such as LDAP, NIS, or JDBC), find all the groups that User1 belongs to, then find all the work items available for the queues with User1 and all the groups to which User1 is a member.
Sometimes external applications need to get all the work items available from one or more queues, and display the list to the members of a queue. In this approach, the external application authenticates the users to access the available work items from one or more queues. The external application may even get the work items list for a queue rather than for a user.
The API that can be used to get a work item list for a queue is
List getQueueWorkItemList(Session, String[], String [])
This option is available for any value of oebps.queues.
List getQueueWorkItemList(Session, String[], String [])