No, there isn't.
Twitter allows adding multiple accounts in their web and mobile apps. AFAIK, the accounts are completely independent and not linked in any manner. I don't think Twitter would do the linking without informing users about it. Even if the accounts are linked in their databases for security reasons, the information isn't publicly available.
Twitter keep redesigning their site and changing things.
It's still possible but what's not clear is that on profile, where it says how many are following and how many you are following, those are actually links.
You can click those and see.
So that text ^ where it says followers, and following, are actually links / you can click.