Thanks for the follow-up, @Annicat.
I've updated my answer to provide clarification about importing the IIF file.
Once you successfully import the IIF file of budgets lists, you can open it by generating the Budgets Overview report.
If you need to view the exported IIF file, you can refer to this article for more information: Export or import Intuit Interchange Format (.IIF) files.
Let me know if you have further questions about the imported budgets. I'll be on the lookout for your reply if you need further help.