You can pre-select a domain to manage before opening the Active Directory Users and Computers snap-in by creating multiple shortcuts or by using the CMD line.

To pre-select the domain based upon domain name, use the /domain=FQDN switch, where FQDN is the Fully Qualified Domain Name, such as JSIINC.COM or childdomain.domain.com.

Example:

dsa.msc /domain=childdomain.domain.com

To pre-select the domain based upon a domain controller, use the /server=FQSN switch, where FQSN is the Fully Qualified Server Name, such as JSI001.JSIINC.COM.

Example:

dsa.msc /server=JSI001.JSIINC.COM