US and Persian naming-conventions do not 'map' onto each other exactly.
It is not clear what is the proper way to list these, in Form I-129F, Part 2, Questions 2a-c.
In the US, everyone has one Last Name (a.k.a. Family Name), sometimes hyphenated. E.g., Smith. Or Smith-Jones.
We have a Given Name (a.k.a. First Name). E.g., Mary.
Many (though not all) have a Middle Name (rarely used). E.g., Katherine.
So the full name would be: Mary Katherine Smith-Jones (first middle last). Or: Smith-Jones, Mary Katherine (last, first middle).
In Iran, the naming conventions are different. Many people have what I'm calling "compound last names" -- one name more specific to a particular family, and a broader name that may have originated from a tribal or village name (even though in theory tribal or village names have been eliminated in modern Iran), and the latter may almost never be used in everyday life.
E.g., the immediate family might be named Arshi, the broader ('tribal/village') family name might be Meradloo. The given name might be Zahra. The full name would be Zahra Arshi Meradloo. But in everyday life the woman would go by just Zahra Arshi or Ms. Arshi (never using the broader name). Her business card might just say "Zahra Arshi," her friends and colleagues would know her only as Zahra Arshi, while her passport might say "Arshi Meradloo, Zahra." (Note that "Arshi" is *not* a Middle Name -- her father's full name might be e.g. Mohsen Arshi Meradloo.)
What and where is the appropriate way and place to list these names in the I-129F?
I'm guessing to put both names in the "Last Name" field (Part 2 Q.2a), like this: Arshi Meradloo
And, of course, for Given Name it is: Zahra
And nothing anywhere else, e.g. no Middle Name, and nothing in Q.10a-c (Other Names Used).
Is that right? (This question must come up with every Iranian-Western K1 aplication. :-) ) I wouldn't want to confuse a US clerk, who might inadvertently think that "Meradloo" is the Last Name, and Arshi is a Middle Name (in the wrong place), or that it should be hyphenated (Arshi-Meradloo), or something like that.