Multiple extensibility action scripts or flows that join pathways together and contribute to the same output. 

version: "1"
action7:   
 action: <action_name>   
 next: joinElement     
action8:    
 action: <action_name>   
 next: joinElement                      
joinElement:
 join: 
   type: all 
   next: action10   
action10:   
 action: <action_name>   
 next: flow_end
Note: You can loop back to a previous action by assigning it as the next: action. For instance, in this example, instead of next: flow_end, you can enter next: action1 to rerun action1 and restart the sequence of actions.
The join action flow allows multiple action flows to join back together into one common output.

Clarification on the join element position on the image. Join Element