I have been searching for an appropriate BADI already, that is implemented in the GET ENTITYSET method... without success. The only BADI which is called before all items are shown in the app is /IWPGW/ES_TGW_TASK_QUERY , but with this I can only change the task title for all items.
Other idea would be to implement a filter option. But when configuring the app i can only ScenarioCollection filter in Launchpad Designer /sap/opu/odata/IWPGW/TASKPROCESSING;mo/ScenarioCollection?$filter=key eq '<your scenario id>.
Isnt there any filter option for WorkflowTaskCollection?