Access Parent workitem summary in ccm workitem
One answer
The Attribute Customization API does not provide means to do that. See https://rsjazz.wordpress.com/2022/11/25/ewm-attribute-customization-introduction/ . Also see https://rsjazz.wordpress.com/2016/07/15/rtc-process-customization-what-you-can-and-cannot-do/ .
Based on this you could only achieve this by internal APIs.