Search nodes with paragraph
The \Drupal::entityQuery object doesnt support JOINs I believe:
https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Entity%21Query%21QueryInterface.php/interface/QueryInterface/8.2.x

If it did you could Join onto the Paragraph bundle and LIKE across that all you want.

I recommend the following approach with Views, a small chance exists it may not work:


Create a View of your case study Nodes
add a relationship to the Paragraph bundle (if needed)
assure the field list for the View includes title and field_rows (you can Exclude field_rows from showing in your view if you want).
add a Grouped Filter and Expose it and select it to use your title and field_rows values.


That should do the trick...