There is an issue in Asana’s “My Tasks” section where tasks cannot be displayed grouped by fields in the Board view, although they can be successfully grouped in the List view. Additionally, when filtering tasks in the Board view to only show tasks due this week, still no tasks are displayed, despite there being a manageable number of tasks. Asana displays an error message “This view contains too many tasks to group them by a field. Group by sections or use another view.”
I think the problem could be that the “too many tasks” is referring to completed tasks that you may have hidden; I’m afraid those still count in the thresholds.
Yes, there is a huge amount of completed tasks in my tasks. Obviously. But in my opinion Asana should be able to handle this amount in the my tasks-views in some clever way without me needing to remove me as assigned or—let alone —delete the tasks all together. Maybe they need to restrict the viewing option in my tasks only to incompleted tasks.
It wasn’t obvious to me that you were asking for a product change.
Please search in Product Feedback to see if anyone has already requested this and Vote at the top of the topic with the Vote button, otherwise create your own request and Vote.