Number of previous companies

Thank you for reaching out regarding your concern about exceeding the limit of recent files shown in QuickBooks Desktop for Mac, AVIDPgh. I am glad to assist you. 

Currently, the feature only allows displaying the 10 most recent files. However, we are always looking to improve our services and provide the best experience to our customers. We value your feedback and suggestions to help us achieve this goal. You can share your feedback by following the steps below: 

1. Click the Help option.
2. Choose the Send Feedback Online option.
3. Press the Product Suggestion option.
4. Enter your feedback suggestion.
5. Hit Send Feedback.

Your valuable feedback goes to our back-end team to help improve your overall experience with QuickBooks.

Meanwhile, I recommend organizing the recent files based on their importance. you can exclude the files which is lesser important. This will make it easier for you to quickly find the files you need. 

Furthermore, if you want to learn how to find and restore your backup company file in QuickBooks Desktop for Mac, you can check out this article: Restore your backup company file for QuickBooks Desktop for Mac

Please feel free to keep in touch with us if you have any further questions about recent files in QBDT for Mac. The Community is always available for you. Best regards. 

This is a macOS setting. Look in Apple->System Settings. Under macOS Sonoma its  at the bottom of the control center.