How its correct in English: Intercultural Nonverbal Business Communication?

It really has to be the first one. It sounds like jargon to me, but it means that the business communication is both intercultural and non-verbal. Maybe it's to do with body language in different cultures. Some like to look you in the eye, some don't. Some cultures find it insulting if you cross your legs and show the souls of your shoes. This could be what it is about.

Both are acceptable but the first choice, i.e. "Intercultural Nonverbal Business Communication" sounds closer to correct English. Your second choice, "Intercultural Business Nonverbal Communication" would be more appropriately worded "Nonverbal Communication in Intercultural Business" or "Nonverbal Communicaiton in International Business". I'm not sure what "Intercultural Business" is, but "International Business" is commonly used and understood. The phrase is not a common one. There might be a shorter way to say what you are trying to describe, and you might improve the quality of your responses here if you could add Details to your question to give examples of what you are trying to describe. For example, I would think that things like a "Nod Yes" or "Nod No" would be a form of nonverbal communication that is understood in business situations, regardles of country or culture, and would therefore be a "Intercultural, Nonverbal Business Communication". I can imagine a signal such as holding your hand up with flat palm outward to say "Stop" would be another. There are many more non-verbal signals one could give that are understood in any culture for business situations. The term "Business Communication" is heard often. So is "Nonverbal Communication". To be totally correct, you should insert a comma after your first descriptive adjective. That is, it should be "Intercultural, Nonverbal Business Communication". If you go with the second phrase, I would change it to "Nonverbal Communication in International Business" because "Intercultural Business" is not well-known or heard often.

It really has to be the first one. It sounds like jargon to me, but it means that the business communication is both intercultural and non-verbal. Maybe it's to do with body language in different cultures. Some like to look you in the eye, some don't. Some cultures find it insulting if you cross your legs and show the souls of your shoes. This could be what it is about.

I'd say "Cross-Cultural Non-Verbal Business Communication." Intercultural does sound like a buzz word and people may be unsure of what it means without your explanation. Most native English speakers would know what "Cross-Cultural" means though. You could also use "Multicultural Non-Verbal Business Communication." Or, even better: Non-Verbal Business Communication in Many Cultures

I'd say "Cross-Cultural Non-Verbal Business Communication." Intercultural does sound like a buzz word and people may be unsure of what it means without your explanation. Most native English speakers would know what "Cross-Cultural" means though. You could also use "Multicultural Non-Verbal Business Communication." Or, even better: Non-Verbal Business Communication in Many Cultures