Clear value of drop down select list field from an automation rule?

[Ann Rumenapp]

I have to write an automation rule that will clear data from 2 custom (drop down select) fields when the epic is removed from the card/issue and the cards/issues sub-tasks.  

The rule currently will update the card when an Epic is changed, but I now need to expand the rule for when the Epic is removed.

The current rule is: 

When value changes for Parent Link (Any changes to the field value; for Edit issue)

• Issue Type is one of Story, Spike, Task, Bug, SecurityRisk, Dependency Task, Technical Debt, Improvement, Discovery, Production Support. Sub-task, In-Sprint Defect task
• THEN edit issue fields 'project', Copy from Parent issue
• THEN edit issue fields 'work type', copy from Parent issue
• Branch: For JQL 'parentEpic = {{issue}}
  • THEN edit issue fields 'project', Copy from Parent issue
  • THEN edit issue fields 'work type', copy from Parent issue