You will have to look at the browser organisation to understand what parameter 'test2' is a value of. This will be one of the parameters associated with the sheets.
Via the API you have limited access to browser organisation
BrowserOrganization.GetCurrentBrowserOrganizationForSheets
The property BrowserOrganization.SortingParameterId may be of interest but in reality the project browser has many levels of sorting/grouping so it doesn't seem current API object fully encompasses that.
There is also BrowserOrganization.GetFolderItems but you have to supply the View.Id of a view within such a folder. Then each such item has properties ElementId (the folder parameter id) and Name (the folder name).
If you are working with a known browser organisation with the same company template then you can establish the above by investigating in the UI.
Regardless 'test2' will likely be a value of a parameter on a sheet.
This is another intriguing example of StorageType.None i.e. BrowserOrganisation object contains parameters named Filter and Folders (not accessible to API).