It's a pleasure to have you here in the Community, reinesdesign.

I've got just the answer you're looking for regarding adding custom reports to favorites.

In QuickBooks Online, customized reports are saved in the Custom Reports tab. At this time, reports listed here can't be added to the Favorites found in the Standard tab of the Reports page.

The good news is, we can manually create a Favorites group in this tab, where we can add the customized reports. Let me walk you through the steps on how to do it:

1. Click Reports in the left navigation menu.
2. Go to the Custom Reports tab.
3. Select the custom report.
4. Click the Save customization button.
5. In the New group name field, enter Favorites.
6. Hit the Add button.
7. Click Save.

Once you're done, here's how we can add the other reports to this group:

1. Go back to the Custom Reports tab.
2. Select the custom report.
3. Click the Save customization button.
4. From the Add this report to a group drop-down menu, choose Favorites.
5. Hit Save.

That should do it. With this information, you'll be adding those reports in no time.

Please keep in touch with me here should you need any further assistance, I always have your back. Thanks for coming to the Community, cheers to continued success.