How to set the Assigned To when state changes in VSTS/Azure DevOps

Question

I have an inherited process from an Agile process. The base process had the following states New, Active, Resolved, Completed. I added several new states, so now it goes New, Triaged, Active, Development Dont, IT Testing Done, Resolved, Confirmed, Completed to better match how it flows through different people.

The process has some built in State change rules, so when it goes from New to Resolved or Active to Resolved the Assigned To changes back to the Created By person. Also when it goes from Resolved back to Active it switches the assigned to back to the Resolved By user. This works fine, the problem that I have is that these state change rules only happen for these specific states.

In VSTS online I have setup some custom rules to do different things as it moves between different states, but what I can't find a way to do is to set the Assigned To field to some other person field on the Work Item. I can set it to a hard coded person, but that is not what I want. I want to do the same state change rules that already exist for the built in states on my new states.

Here is an example of some of the rules that I have set, but I cannot find a way to set the Assigned to field to another field, i.e. Created By or Resolved By.

Answer 1

Use the copy value from to assign the value of one field to another: