I'm on Jira Server and I'm utilizing Automation for Jira to populate an Assignee List field (multiple user picker field). The Assignee List is set based off of the Component(s) selected on the ticket. If multiple Components are selected, the current rule that I have set up now overwrites the existing values, and only allows me to set one member in the Assignee List.
I need a way to append to the field rather than overwrite it.
There are 12 or so Components set up, so assume that someone comes in and selects each Component. I need each of the 12 members that correspond to a Component set in the Assignee List field without being overwritten.
Any help is much appreciated!!
I'm going to assume that your "Assignee List" field is a custom field.
Given that, it looks like you've run into a limitation of Jira Automation that, frankly, Atlassian should fix. I'd suggest letting Atlassian Support know that this is a problem for you.
If they open or identify a ticket, post it under this question -- I'll vote for it (as will others who find this thread).
(ProTip: Don't post links to "PCS-xxx" tickets, as those are specific to you and not visible to others -- I mean a link to an issue in the Jira database).
Note that Automation does provide some "list editing" capabilities for some multi-select fields, like "Labels", under "Operations > Add/remove values":
However, you've discovered that a custom field with multi-select values isn't supported like this. Heck, even the built-in "Components" multi-select fields doesn't support this. Grrrr.
If you want to go down a rabbit-hole to accomplish your goal another way, the "More options" link will let you get into JSON and coding to manipulate the lists related to issue fields. There are some limitations there too, but maybe you can accomplish your goals that way. If you don't have a development background, be warned that there's a steep learning curve - you can start your journey here.
Unfortunately, I don't have any other good options for you on this, sorry.