Hi,
You will need to customize the UniGrid control used for this UI page.
So, you will need to get some information from the Staging_Task table for each task such as TaskNodeID - using this ID you can get information about given node and document using our API, for example SelectSingleNode method will return you all the data from CMS_Tree and CMS_Document tables including the user ID - DocumentLastModifiedBy column from CMS_Document table. So, then you can use it to display it in the list.
Best regards,
Juraj Ondrus