Are you talking about the Brazil that is famous for its soccer?
Are you talking about the country of Brazil which is so famous for its soccer?
この場合、次のような言い方をすると自然で良いかなと思います。
ーAre you talking about the Brazil that is famous for its soccer?
「サッカーで有名なあのブラジルのこと言ってるの？」
ーAre you talking about the country of Brazil which is so famous for its soccer?
「サッカーですごく有名な国のブラジルのこと言ってるの？」
Are you talking about ... that is ....?
Are you talking about ... which is ...?
を使って表現すると良いでしょう。
ご参考まで！
カナダ 
