In our organization we have number of SQL Server instances which are grouped by their Business Unit, Environment (PRD, DEV etc). For new joiners, it is hard to find out the list servers in absence of CMDB. As a solution, you can ask your team member to give you the list of registered servers by doing using server import/export option.
1. In Registered Servers, right-click a server group, and then click Export.See below image for more information.
2.In the Export Registered Servers dialog box, from the Server Group list select the location where you would like to save the registered server information, in the Export file box type a name for the exported file, and then click Save.