Begin by SSH to your VCSA.
Run the following command to discover your SSO Domain Name:
/usr/lib/vmware-vmafd/bin/vmafd-cli get-domain-name --server-name localhost
Command to discover your SSO Site Name:
/usr/lib/vmware-vmafd/bin/vmafd-cli get-site-name --server-name localhost
Another option is to use the vdcrepadmin tool with the showservers switch, this will display all of the PSC Appliances and their associated Sites and Domains within the single SSO Domain:
/usr/lib/vmware-vmdir/bin/vdcrepadmin -f showservers -h localhost -u administrator