How should I fix the problem of two part surname taken as middle name by google scholar?
Google crawled your data from somewhere, I suspect that source gave Google the wrong data. E.g., perhaps a bibtex listing is wrong. So, to fix the problem, you could fix the source.
Taking Mahmoudi as the middle name in Alireza Mahmoudi Kamelabad is a standard reading. To avoid that reading, you could use Alireza Mahmoudi-Kamelabad in the future.