Database discovery module discovers database as service name

Hello experts,

Recently we have installed OEM 13.5 in a new Linux server and installation is successful.In one of the ODA server we are running at least 30 databases.When we ran auto discovery it found all the databases but it is showing as dbname.domainname which is the default service.We dont want to display domain name and to rename discovered name for 30 databases are very time consuming.

My question is why discovery module discovers name like that? Is there any technique by which we can instruct discovery module so that it does not append domain name.

If above is according to design and not possible then is there any emcli command to rename before targets are promoted.