You can view and process Grab activities in WorkSpace if you have the required role. If the instance is sitting in an activity that has an implicit or explicit transition to a Grab activity, an icon appears next to it to indicate that you can grab this instance.
After you complete the main task the instance flows to the next flow object according to the explicit or implicit transitions. If the Grab activity is of the type From All/To All, it allows the user to select where it should flow.
You can search for instances sitting in a Grab activity or define a view that includes them. To view the instance details select the instance in the search result or in the view.
You cannot grab an instance that is sitting in another Grab activity.