title: LINQ Query over another LINQ query
body: <p>Is there a way to Query over another LINQ query?</p>
  
  <p>I have a BindingSource object that contain the result of a LINQ expression. and that BindingSource is the DataSource of a DataGridView.  </p>
  
  <p>Now I would like to filter futher more the result of the BindingSource.</p>
  
  <p>Is there a way to convert that BindingSource DataSource to soemthing I could query?</p>