You can use the “Set Multiple Variables” module, to set an array variable for each variable you want to split into an array.
Then, use the Iterator module to only iterate one of the array variables.
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!