Currently, this is not possible, if you were to change the case folder for a case that is apart of a Companion group it will change all the case folder links to that one folder; however, whenever you have them seperated from the companion group and set to nested folder, the files inside of Case Docs reflect the nested folder they were set to; however, the folder link will not display correctly. It would be best to be able to set their case folder to a nested folder inside of another case folder, so we can group up the companion cases and all of the sharepoint documents to the main case.