file that I used to test C# Sublime plugin indentation in Symbol List: https://github.com/laughedelic/SublimeCSharp

symbol-list-tester.cs

namespace FooNamespace
{
    class Class
    {
        static void Method1(){}
        static void Method2(){}

        class InnerClass
        {
            static void InnerMethod1(){}
            static void InnerMethod2(){}

            class InnerInnerClass
            {
                static void InnerInnerMethod1(){}
                static void InnerInnerMethod2(){}
            }

            static void InnerMethod3(){}
        }
    }
    
    class Class
    {
        static void Method1(){}

        class InnerClass
        {
            static void InnerMethod1(){}

            class InnerInnerClass
            {
                static void InnerInnerMethod1(){}
                static void InnerInnerMethod2(){}
            }
        }

        static void Method2(){}
    }
}

#region Region

namespace BarNamespace
{
    class Class
    {
        #region InnerRegion

        static void Method1(){}
        static void Method2(){}

        #endregion
    
        class InnerClass
        {
            static void InnerMethod1(){}
            static void InnerMethod2(){}

            #region InnerInnerRegion

            class InnerInnerClass
            {
                static void InnerInnerMethod1(){}
                static void InnerInnerMethod2(){}
            }

            #endregion

            static void InnerMethod3(){}
        }
    }
}

#endregion