@lisastelter
What did you actually do? It's not clear, because your post indicates a "Nest Doorbell (battery)", but if that's the doorbell you have, then you would already be using a Google Account for your Google Nest devices, and so could not "migrate" from a Nest Account to a Google Account, AND you cannot "transfer" a Nest Doorbell (battery) from the Google Nest app to the Google Home app because it's already in the Google Home app.
Did you migrate your Google Account to a Nest Account? If that's what you did, then you should log into the Google Nest app using the Google Account to which you migrated, but you should also be able to see your 1st gen doorbells in the Google Home app. (See this Help topic: https://support.google.com/googlenest/answer/9297676.)
Or did you transfer each of your 1st gen doorbells from the Google Nest app to the Google Home app? If that's what you did, then you should be able to see your old, existing video history in the Google Nest app, but you will have to use the Google Home app to access your new video history going forward. (See this Help topic: https://support.google.com/googlenest/answer/13038234; "All your new camera history is now stored and accessible in the Google Home app and on Google Home for web. Any camera history in the Nest app is accessible until it expires."). And you should be able to continue logging into both the Google Nest app and the Google Home app using your Google Account as you were before the transfers.
