The Unenroll from THIS Journey flow node allows you to unenroll a contact from this Journey (Fig 1). 

Fig 1

While you may click the Unenroll from THIS Journey node and bring up the Properties popup, there are no user inputs available. This node simply removes the contact from the Journey's funnel (Fig 2). 

Fig 2

The possible Flow options are:

• Delay for a Period
• Delay until a Date
• Delay until an event
• Enroll in Another Journey
• Unenroll from Another Journey