You folks can chat all you want about Chinese, but this is Vietnamese and English. The Vietnamese "Bạn lấy mẫu vật đó ở đâu? " here cannot be translated into the English "Where do you take that sample?". The Vietnamese essentially asks where the sample is taken from. But the given translation implies that the asker wants to know where the sample is being taken (to).
I do not care whether they fix the original Vietnamese sentence, or the translated English, but one of them needs to change because they do not match.
Now it is "where did you take that sample" when the Vietnamese version had no indication that it was past tense.