This function lets you view the sleeping tasks for all / specific process instances for the selected process definition. 

On the Process Definition page, select the process from the table and click on the View - Process Task View menu option.

The Process Task View is rendered on the new page. Here, tasks across all sleeping instances of this process definition are displayed in a table. Use the Select Instance drop-down list to view specific tasks. Use the Search box to narrow down the result list.