Hi there,
I'm new to Jira Automation (Cloud) and trying to create an automation rule that creates subtasks for users in a selected group from a custom single group field. yep, not an easy task for a beginner...
What I try to achieve

This screenshot shows my idea how to achieve my goal, but is not finished yet.
However, I managed to iterate over a given hardcoded groupName (in web request) and get users from it to create the subtasks.
Assume the variable groupName is a group name with spaces in it. Unfortunately https://mydomain.atlassian.net/rest/api/3/group/member?groupname={{groupName}} only works if the group has no spaces in it.
Obviously it must be encoded for use in url, and I until now I was not able to do this.
So I decided to us the group id and request the api: https://mydomain.atlassian.net/rest/api/3/group/member?groupId=123456789
This might work with a single, harcoded groupid in Web request URL.
My Problem
However, my problem is quite simple: When I switch from hardcoded groupId/groupname (in web request url) to retrieving groupId from custom single group field, the value is always null.

My custom field has the name "Training Group" with the field id "customfield_10322".

"https://mydomain.atlassian.net/rest/api/3/issue/<issue-key>?expand=names" shows that the following attributes are available for customfield_10322
"customfield_10322": {
"groupId": "123456789",
"name": "Training group",
"self": "https://mydomain.atlassian.net/rest/api/3/group?groupId=123456789"
},
However, I can't get the groupId attribute via smart value. The value is always null.

Neither with SmartValue {{issue.customfield_10322}} nor {{issue.customfield_10322.groupId}} or {{issue.fields.customfield_10322.groupId}}.
To simplify things, I've created a manually triggered rule that logs to the audit log.

I'm curious to know what's my mistake and would really appreciate your tips.
If there is a better or simpler solution for my goal I would like to hear your suggestions.
Thanks in advance, this is driving me crazy for hours...
Regards, Tim