Transfer custom field values to Services and Organizations

[Matt S]

We are in the midst of migrating our Jira instance to cloud and used a particular app (STAGIL Assets) for asset management in server. This app enabled the creation of the Relation custom field type which will not migrate using the migration assistant, from my understanding. We had two primary fields using this type, corresponding to the applications and departments related to a particular issue. The titles of these departments and applications were represented as issues in a separate Jira project, each with a distinct issue key. As part of the migration, we are investigating options for translating these issue keys into services and organizations within cloud. I am interested in whether cloud automation supports the use of key (Old issue keys)/value (Service and Organization names) pairs for editing relevant issues. 

What I'm dreading is the need to create separate rule conditions for each key and manually assign each Service/Org in an associated action.

Currently, I have copied the plain text issue keys into a separate custom field within our server instance.