public abstract class Instance : DynamicObject
{
        public Dictionary<string, Instance> Children = new Dictionary<string, Instance>();

        public override bool TryGetMember(GetMemberBinder binder, out object result)
        {
            Instance value;

            if (Children.TryGetValue(binder.Name, out value))
            {
                result = value;
                return true;
            }

            return base.TryGetMember(binder, out result);
        }
}

public class Workspace: Instance
{
}

public class Part : Instance
{
}

var workspace = new Workspace();
workspace.Children.Add("Part", new Part());

var global = new LuaGlobal(_lua)            
{
    ["workspace"] = workspace,
};

var chunk = _lua.CompileChunk("print(workspace.Part)", "test", new LuaCompileOptions());
var result = global.DoChunk(chunk);

print(workspace.Part)