I have a requirement where user wants to notify the approval of a task to a group of users for further action. When the group receives the notification, the first person who choose can assign the task to themselves. Subsequent users who try to open the task should be able to see who is currently holding the task. The workflow should be in the "pending" state at this point. Once the person has completed the work, he/she can go back and choose to complete the task and the workflow ends notifying everyone that the task has been completed. Can someone please direct me to the right place or actions to accomplish this in the nintex 2013 workflow?