How do I get a value automatically selected from a custom field after a transition occurs?

[John_Diaz]

Context: So when a transition happens from a workflow perspective, a new project ticket opens and there's a custom field that I want a specific value to be chosen once it opens the new ticket and links to the original. 

Please see my screenshot from the post functions tab.  I've highlighted the custom field and value I want updated in the new ticket that eventually gets open after the transition occurs. 

Am I inputting it wrong?  It picks up everything else but the "set custom field" after the transition.