Get a JSON with the values of a Checklist custom field of Checklist for Jira from the transitioned issue using the Jira’s Get Issue REST API.
In Expert mode, create a new action with the following parameters:
Enter Get Checklist as the name of the new action.
Select the GET method.
Select the connection with the current instance.
Use the following REST path.
/rest/api/2/issue/{issueIdOrKey}
For the REST path parameter issueIdOrKey, select the field Issue key.
Update a Text field with the following expression after replacing the ID of the Checklist field with the appropriate one:
%{action.response.fields.customfield_aaaaa}
In order to obtain a particular value of the field, you should further specify the JMESPath query for the field code.
Add more steps according to your needs.
Execute remote action