Hi!
Thank you for posting your query to community forum!
Unfortunately, Windows 11 does not support taskbar toolbars like in Windows 10.
However, you can still access a nested folder tree structure by using the Start menu or File Explorer. You can pin frequently used folders to the Start menu for quick access or create shortcuts on your desktop for easy navigation. While it may not be as seamless as taskbar toolbars, these alternatives can help you maintain productivity. There are third party tools available which you can try such as ExplorerPatcher, StartAllBack.
Please note that Microsoft does not officially recommend or support third-party applications for modifying the Windows 11 taskbar. While some tools may help restore lost functionality, they can also introduce potential security and stability risks. If you choose to use such apps, it's important to download them only from trusted sources and be mindful of any unintended effects on your system.
If you're missing a feature in Windows 11, the best way to let Microsoft know is by submitting feedback through the Feedback Hub:
Send feedback to Microsoft with the Feedback Hub app - Microsoft Support
I hope answers your query but if you need further assistance feel free to reply.
Best regards,
Scott | Microsoft Community Moderator.