title: Filter a list by another list C#
body: <p>I have the following business objects:</p>
  
  <pre><code>    public class ItemCategoryBO
      {
         public string ItemCategory { get; set; }
         public string Title { get; set; }
      }
  
      public class ItemBO
      {
         public int ItemId { get; set; }
         public string Title { get; set; }
         public string ItemCategory { get; set; } 
      }
  
      List&lt;ItemCategoryBO&gt; categoryList = new List&lt;ItemCategoryBO&gt;();
  
      ItemCategoryBO itemCategory = new ItemCategoryBO();
      itemCategory.ItemCategoryCd = "CARS";
      itemCategory.Title = "Cars";
  
      ItemCategoryBO itemCategory2 = new ItemCategoryBO();
      itemCategory.ItemCategoryCd = "PLANES";
      itemCategory.Title = "Planes";
  
      categoryList.Add(itemCategory);
      categoryList.Add(itemCategory2);
  
      List&lt;ItemBO&gt; itemList = new List&lt;ItemBO&gt;();
  
      ItemBO item1 = new ItemBO();
      item1.ItemId = 1;
      item1.Title = "1st item";
      item1.ItemCategoryCd = "OTHER";
  
      ItemBO item2 = new ItemBO();
      item2.ItemId = 2;
      item2.Title = "2nd Item";
      item2.ItemCategoryCd = "CARS";
  
      ItemBO item3 = new ItemBO();
      item3.ItemId = 3;
      item3.Title = "3rd Item";
      item3.ItemCategoryCd = "PLANES";
  
      itemList.Add(item1);
      itemList.Add(item2);
      itemList.Add(item3);
  </code></pre>
  
  <p>If I have a list of a few categories, how could I find a list of items that contain a category in the list of categories? (In my example, I want to get back items 2 and 3)</p>