using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var isUser = false;

        var entities = new List<EntityThing>

        {

            new EntityThing

            {

                IsVisible = true,

                IsVisibleToUser = true,

                Foo = "User Visible"

            },

            new EntityThing

            {

                IsVisible = true,

                IsVisibleToUser = false,

                Foo = "User Not Visible"

            },

            new EntityThing

            {

                IsVisible = false,

                IsVisibleToUser = true,

                Foo = "Not Visible"

            }

        };

        var query = entities.Where(e => isUser 

                                   ? e.IsVisible && e.IsVisibleToUser 

                                   : e.IsVisible && !e.IsVisibleToUser);

        foreach (var q in query)

        {

            Console.WriteLine(q.Foo);

        }

    }

}

​

public class EntityThing

{

    public bool IsVisible { get;set;}

    public bool IsVisibleToUser {get; set;}

    public string Foo {get;set;}

}