Example of registering multiple implementations of IConfigurationOptions<TOptions>

StartupWithMultipleConfigurationOptions.cs

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSingleton<IDateTimeResolver, DateTimeResolver>();
        services.AddMvc();
        services.AddOptions();
        services.Configure<MySettings>(Configuration.GetSection("MySettings"));
        services.AddSingleton<IConfigureOptions<MySettings>, ConfigureMySettingsWithHello>();
        services.AddSingleton<IConfigureOptions<MySettings>, ConfigureMySettingsWithWorld>();
        services.AddSingleton<IConfigureOptions<MySettings>, ConfigureMySettingsWithDateAndTime>();              
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseBrowserLink();
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseStaticFiles();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
    }
}