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

Yes

The word "Tiago" is a proper noun (a person's name), so its meaning, spelling, and grammatical function are identical in both Brazilian and Continental Portuguese. The only difference lies in pronunciation:

• Brazilian Portuguese: In many regions (such as Rio de Janeiro and São Paulo), the "t" before the "i" is palatalized, meaning it sounds like the "ch" in the English word "cheese" (e.g., chee-ah-goo).
• Continental Portuguese: The "t" is pronounced as a dental or alveolar consonant (a much sharper "t" sound), and the vowels are typically more closed or reduced.

Brazilian Portuguese Examples

1. O Tiago está chegando agora. (Tiago is arriving now.)
2. Eu chamei o Tiago para o lanche. (I called Tiago for a snack.)
3. O Tiago é muito gente boa. (Tiago is a very nice guy.)
4. Você viu o Tiago na escola? (Did you see Tiago at school?)
5. O Tiago gosta de comer coxinha. (Tiago likes to eat coxinha.)

Continental Portuguese Examples

1. O Tiago está a chegar agora. (Tiago is arriving now.)
2. Eu chamei o Tiago para o lanche. (I called Tiago for a snack.)
3. O Tiago é muito porreiro. (Tiago is very cool/nice.)
4. Tu viste o Tiago na escola? (Did you see Tiago at school?)
5. O Tiago gosta de comer pastéis de nata. (Tiago likes to eat custard tarts.)