To allow domain administrator to access his domain control panel, please follow the following steps :-
1) Log in to your Plesk control panel.
2) Click on "Domains" .
3) Click on domain name for which you want to allow domain administrator access.
4) Click Domain Administrator Access (In the Domain Administration group).
5) Select the Allow domain administrator access check box, type the password for
access to control panel (The domain administrator's login name is always his or
her domain name), fill in the contact information and specify the operations the
user will be able to perform through his control panel.
Click on "OK" once you have inserted the permessions.
You can now login to your domain Plesk control panel by using following URL "https://domainname.com:8443"
