You can use deep link to link a particular page and in the google console you can use redirect uri as that link. then after allowing an google acount from iframe window, it will redirect you to deep linking page that you provided in redict uri.
You can use the deeplink module. Or use a custom URL for each page. In the redirect to Google you can add “&cont=<URL>” to the querystring. Mendix will pick up that continuation string and redirect to the deeplink or static URL. If it is not implemented in your solution with OAuth yet, you can look at the SAML2 module to see how it is implemented in Java.