Its just adding a secondary condition to the events in the group. they won't activate until both conditions are met. you can use the secondary event condition to control when actions can be set. so you have a group of events you want to be active only once? you just set an action where you want the group action to end to change the variable thus eliminating the statement of the secondary condition.
I don't see how this adds whole new events just conditions within an event and an addition action where the group of events end.