Hi @Sandy Hays , Welcome to our forum!
Do you mean that when you select a folder in New Outlook for Windows and then select another folder, the sub-folders of the previous folder will be automatically collapsed?
If so, i'm afraid that it is not available in New Outlook for Windows.
Please kindly understand that many functions are not designed at present. It is recommended that you could post the functions you expect and your sincere suggestions on the website dedicated to collecting feedback. We sincerely welcome your suggestions, and thanks for your understanding and support!
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.