Team Opera, There's no such way/setting to open any link, website or domain in other related apps from Opera. Which is really inconvenient for Opera users. Even though i think it's a basic standard browser feature.
Users are unable to get redirect from a domain(in Opera browser) to another domain (outside Opera browser). For example: you can't get redirect from https://m.youtube.com/ (in Opera browser) to YouTube application(outside Opera browser), and its same with Gmail, Google, Maps or any other services/apps.
There should be a way/setting through which users could choose to open a domain in opera browser or in the related applications.