○○と関係ない○○でって英語でなんて言うの？

差別と関係ない議論でなぜ差別を引き合いに出すの？= Why are you referring to discrimination in a discussion with no connection to discrimination?

領土問題と関係ない動画でなぜ領土問題についてコメントをするの？= Why are you commenting on territorial problems in a video without a link to territorial problems?

元の話と関係ない話題で話を進めないでください = Please don't continue talking about something that has no connection to what we were talking about before.

それは私と関係ないお話ですね = That's a conversation that has nothing to do with me.

このように書いた文は英語で言えると思います。

参考になれば幸いです。