A Work Item can be run under any tab of the Sentinel Control Center.
A Work Item can be processed while still in a Group and not acquired by a user. However, once a step is completed and the next step is of the same group, the step will be acquired by the user.
After acquiring a Work Item steps in succession that belong to a Group and has been acquired by a user, the Work Item will stay with the user.
If a single of succession of steps are with a user followed by a step of another group and returns back to the original role, the step will not revert to the user. It will be assigned to the group.
The two stages of processing a work item are
Accepting a work item
Completing a work item