Index parameter fails on nested collections about gridify HOT 5 CLOSED

l1 =>  l1.Level2List.Any(x => (x.Level3.Level4List[0].Property1 > 5))

using Gridify;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApp1
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            var test = new Test();
            test.Run();
        }
    }

    public class Test
    {
        public void Run()
        {
            List<Level1> level1List = new List<Level1>();
            level1List.Add(new Level1());

            var gridifyMapper = new GridifyMapper<Level1>().GenerateMappings()
                .AddMap("level4_property1", (q, index) => q.Level2List.Select(x => x.Level3.Level4List[index].Property1));

            var gridifyQuery = new GridifyQuery() { Filter = "level4_property1[0] > 5" };
            var expression = gridifyQuery.GetFilteringExpression(gridifyMapper).Compile();

            var query = level1List.Where(expression);
        }
    }

    public class Level1
    {
        public string Name { get; set; }
        public Level2[] Level2List = new Level2[]
        {
            new Level2()
            {
                Name = "1",
                Level3 = new Level3()
                {
                    Name = "2",
                    Level4List = new List<Level4>()
                    {
                        new Level4() {Name = "3", Property1 = 3, Property2 = 4},
                        new Level4() {Name = "4", Property1 = 4, Property2 = 5},
                        new Level4() {Name = "5", Property1 = 5, Property2 = 6}
                    }
                }
            },

            new Level2()
            {
                Name = "6",
                Level3 = new Level3()
                {
                    Name = "7",
                    Level4List = new List<Level4>()
                    {
                        new Level4() {Name = "8", Property1 = 8, Property2 = 9},
                        new Level4() {Name = "9", Property1 = 9, Property2 = 10},
                        new Level4() {Name = "10", Property1 = 10, Property2 = 11}
                    }
                }
            },

        };
    }

    public class Level2
    {
        public string Name { get; set; }
        public Level3 Level3 = new Level3();
    }

    public class Level3
    {
        public string Name { get; set; }
        public List<Level4> Level4List = new List<Level4>();
    }

    public class Level4
    {
        public string Name { get; set; }
        public double Property1 { get; set; }
        public double Property2 { get; set; }
    }
}