To display filter options in the individual columns, click on the funnel icon in the respective column.
Example: You have grouped the task list according to a specific employee and now want to see only the tasks of this employee in the "Fair" project. To do this, click on the magnifying glass icon in the Project Name column. In the drop-down menu that opens, select the filter criterion = Equal. Now enter the word "Fair" in the search field next to the =. Now only the tasks of the employee from this project are displayed.