One root folder 2 subdomains

Hello everyone
Can someone hint me decision…
I have one root folder in var/www/html/mydomain
and 2 subdomain
1. sub1.mydomain.com
2. sub2.mydomain.com

when I type sub1.mydomain.com in a browser, it opens required index.php.. It os ok
But when I type sub2.mydomain.com it opens the same page, but I need sub2.mydomain.com/tpm/login.php to be opened (login.php located in /var/www/html/mydomain/tpm directory)

How do I fix this simple issue’;