Is the word mundial the same in Brazilian and European Portuguese?

Yes

The word "mundial" is identical in meaning, spelling, and grammatical function in both Brazilian and Continental Portuguese. The only difference is in pronunciation. In Brazilian Portuguese, the vowels are typically more open and clearly articulated. In Continental Portuguese, unstressed vowels are often more closed, reduced, or even nearly deleted, which gives the word a more "consonantal" sound to Brazilian ears.

Brazilian Portuguese Examples

1. Ele é um artista mundial. (He is a worldwide artist.)
2. A empresa busca expansão mundial. (The company seeks worldwide expansion.)
3. O campeonato mundial de natação começou. (The world swimming championship has started.)
4. Esse é um problema de escala mundial. (This is a problem of worldwide scale.)
5. A música é um sucesso mundial. (The song is a worldwide success.)

Portuguese (Portugal) Examples

1. Ele é um artista mundial. (He is a worldwide artist.)
2. A empresa procura expansão global. (The company seeks global expansion.)
3. O campeonato mundial de natação começou. (The world swimming championship has started.)
4. Este é um problema de dimensão mundial. (This is a problem of worldwide dimension.)
5. A música é um sucesso mundial. (The song is a worldwide success.)