If you have a free account, your history is limited to 1 week. If you have a Pro account, you can view your entire history.
To see your history for a specific folder, you can go to the folder view, click on the folder and then turn off the "hide completed tasks" filter. You could also create a saved search that shows completed tasks per folder.
Thank you for really fast reply, but I'm not able to do what you advice.
I go to View by Folder - select a folder but I dont find a "hide completed tasks" to turn off . I'm only able to find a "show recently conpleted" and this shows me only recently tasks.
(I've found my completed task list with an advanced search but I'm curious about your way)
Sorry, you are right. The search method is the only way to do it at this time. I was remembering wrong.
The "show recently completed" filter used to be "show all completed", but we changed this a little while ago because after several months (or years) of use, this could cause a ton of tasks to be revealed and most people are probably only interested in tasks that they completed recently. Tasks that you completed 5 months ago are probably irrelevant, so we hide them in most situations. Using the "History" link will reveal them, but if you need to see only 1 specific folder, then you will need to use the search tool.
I have just subscribed to Pro account so I can see entire history. I just want to be able to generate a basic status report that gives active tasks by folder and then completed tasks by folder. You can sort Recently Completed in this way but as soon as you try to sort the entire history in the same way you exclude all items but Recently Completed. Help!