using System;

using System.Collections.Generic;

using System.Linq;

​

class Entity

{

    public string Id { get; set; }

    public IEnumerable<string> TagIds { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        var entities = new List<Entity> {

            new Entity { Id = "A", TagIds = new []{ "foo", "bar", "baz" } },

            new Entity { Id = "B", TagIds = new []{ "foo", "bar" } },

            new Entity { Id = "C", TagIds = new []{ "foo", "dolor" } },

            new Entity { Id = "D", TagIds = Array.Empty<string>() },

        };

        var query = new[] { "foo", "bar" };

        var results = entities.Where(entity => query.All(Id => entity.TagIds.Contains(Id)));

        // writes A and B

        foreach (var result in results)

        {

            Console.WriteLine(result.Id);

        }

    }

}