sure. Your chart follows some dimension surely. That is a field you can refer to. So in the edit_field for your text, just insert an IF_construct with the GetselectedCount() function to identify whether that field has been selected on - which is the case when the bar has been clicked on.
=> Sth like >> IF(Getselectedcount([dimension_field]) >= 1,' ', '[text]') <<
=> That way, when one of the bar in your chart has been clicked, that text would be empty. (don't forget to put a transparent background to your text)