AdministratorPages.cs

// Pages constants class
public class AdministratorPages
{
   public const string Base = "/Administrator";
   public static string Index = $"{Base}/Index";
   public static string EmployeesIndex = $"{Base}/Employees/Index";
}

// Usage in a View
<a asp-page="@AdministratorPages.Index">Administrator Home Page</a>

// Usage in a PageModel for Redirects
public IActionResult OnPost()
{
    // Do something
    return RedirectToPage(AdministratorPages.Index);
}