Under Folder object URL disapears depending on selected Scope
URL topic provides a hyperlink in eB Explorer View which opens website in object Pane. Mostly they are used with SSRS integration.
URL topic is present in Folder type objects and they differ from other eB Objects as they don't have same security manageability. These URL objects are tied with Scopes, so to view URL you need to have access to scope it was created on. Access to Scope is requires to make this Scope Active otherwise you won't be able to see these URL. It's not required to set the scope as Default to see URL created on that scope.
If URL is required to be visible on all scopes, then it needs to be created on Global scope as Global scope can't be turned off.