Where do I put the sitemap for the fourth level domain?

Where should I put the sitemap.xml file in case of fourth level domain (for example en.subdomain.example.com)?

From sitemaps.org:

All URLs listed in the Sitemap must reside on the same host as the
Site Map. For example, if the Sitemap is located at
http://www.example.com/sitemap.xml, cannot include URL of
http://subdomain.example.com. If the Sitemap is in
http://www.example.com/myfolder/sitemap.xml, cannot include URL
from http://www.example.com.

Does that mean you should put a different sitemap.xml file in the root directory of each subdomain? E.g:

example.com/sitemap.xml - for links ~ https://example.com/path
subdomain1.example.com/sitemap.xml - for links ~ https://subdomain1.example.com/path
subdomain2.example.com/sitemap.xml - for links ~ https://subdomain2.example.com/path
en.subdomain1.example.com/sitemap.xml - for links ~ https://en.subdomain1.example.com/path
fr.subdomain2.example.com/sitemap.xml - for links ~ https://fr.subdomain2.example.com/path

I currently have a sitemap.xml file at the root of https://example.com/, which includes all the links from all subdomains.