The Event Vulnerabilities to Threats page allows you to define the contributions (Vulnerabilities Grid) in a mindmap or chart format.
You can select the event by clicking on the events list:
The connected source nodes to the event node are the sources the event is vulnerable to.
You can add a new event by clicking
A modal will pop out where you will enter the event names -- one event per line.
You can assign the selected event to a (1) new or (2) existing threats/sources by clicking 
(1) For new sources, simply add one source per line
(2) For existing sources, check the checkbox to the left of the sources the selected event is vulnerable to.
