but maybe it’s better to look for flexible BPMN as CMMN seems not to work in the latest version of the Modeler anymore: Cleanup CMMN from the modeler, or at least remove the option to enable it through flags. · Issue #3033 · camunda/camunda-modeler · GitHub.
More about flexible BPMN processes can be found here: Building flexibility into BPMN models | Camunda Platform 8
Hope this helps, Ingo