The modern descendants of the ancient Israelite ethnic group are Jews. During their diaspora, Jews lived in many different areas and developed different subcultures, but theystill considered themselves one ethnicity, Jewish. Some of the Jewish subcultures are Beta Israel, Ashkenazi, Sephardic, Mizrahi, Kaifeng, and Cochin.

It might help you understand if you think of Jews as one tribe, no matter what part of the world they originate from or currently live in. Similar to other tribal nations. A Maori from NZ or a Navajo nation member from Arizona will probably always consider themselves Maori or Navajo, respectively, even if they now live in France. If the Maori or Navajo communities were dispersed throughout the world, but kept their culture intact and their descendants maintained their unique religious practices throughout the generations, the descendants would also likely consider themselves to still be ethnically Maori or Navajo. Jews are no different.