下午好 (xià wǔ hǎo) in Mandarin Chinese can be translated to "Good afternoon" in Engpsh.
The origin of "Good afternoon" as a greeting dates back to the 15th century, when it was used to wish someone well during the latter part of the day. It became a commonly used greeting in Western countries during the 19th century, especially in England and the United States.
Example Engpsh sentences:
Good afternoon, how are you today?
Can I help you with anything this afternoon?
Translated to Chinese:
下午好，今天怎么样？
今天下午有什么我可以帮忙的吗？