Product design. An enhancement request (TF00648946) has been created detailing the feature: Manage the order of domains listed in the User and Helpdesk’s drop down list.
The order that the domains are presented in is the order that they were added to the Management Policy’s User scope.
You can change the order by removing and re-adding the domains to the Management Policy’s User Scope in the order that you want them to appear. If you have different Management Policies for each managed domain, then the policies should be created in the desired order.
The product team will evaluate the request and this feature may become available on a future release of the product.
Please refer to this article for updates or contact support referencing the Enhancement Request ID: TF00648946.