Unfortunately, there is no built-in option to disable grouping by time in the Open/Save file dialogue in Windows 11. However, there are a few workarounds you can try.
1. Use the search bar: Instead of navigating through folders, you can directly search for the file using the search bar in the Open/Save dialogue. This will bypass the grouping by time and display all the results that match your search query.
2. Use a third-party file dialogue: You can use a third-party file dialogue such as FileBox eXtender, which allows you to customize the Open/Save dialogue to your liking. With this application, you can disable grouping by time and configure the dialogue to your preferences.
3. Modify the registry: This is an advanced option and should only be done if you are comfortable modifying the Windows registry. Open the registry editor by pressing the Windows key + R, type "regedit" in the box, and press enter. Navigate to the following key HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\CurrentVersion\Comdlg32 and create a DWORD value called "NoFileMru" with a value of 1. This should disable grouping by time in the Open/Save dialogue. However, be aware that modifying the registry can be risky and may cause system instability if done incorrectly.
I hope these options help you achieve the desired result.