This is the 547th most frequent Turkish word.
önümüzdeki
"Önümüzdeki" means "upcoming" or "next" in English.
In this sentence, 'önümüzdeki' means 'next' and is used to describe the upcoming week (time concept).
Önümüzdeki hafta tatile çıkıyoruz.
We are going on vacation next week.
Here, 'önümüzdeki' means 'in front of us' and is used to indicate the relative location of the door to the speakers.
Önümüzdeki kapının rengi çok güzel.
The color of the door in front of us is very beautiful.
In this context, 'önümüzdeki' refers to the upcoming or next (future) exam in a temporal sense.