Re: Transfer progress to new account apex legends Xbox
No, that'd technically be your brother's progress despite the fact that you played. Unfortunately you'd have to start from scratch, same if you were migrating from XBOX to PC or from XBOX to PS, etc. etc.
But! I could be wrong. Perhaps if you submit a support ticket with your brother's XBOX account name and the name of the one you want the progress to be swapped over to they might help you out.