TMGR: Cannot Filter for Summary Tasks

WORKAROUND

1. Double-click the Folder icon of each expanded summary task to collapse the subtasks. -or-
   
   
2. Highlight the names of all the tasks that you want to collapse to the first level, and click the Hide Subtasks button on the toolbar. Do not highlight the entire column by clicking the column heading; otherwise, the Hide Subtasks button will not work.