This idea has been merged into another idea. To comment or vote on this idea, please visit WEBFLOW-I-89 A better Symbol panel.
Have you made a mistake with your symbols and want to delete all of the instances at once? In the symbol library under the add section it lists all your symbols. It then states how many instances are on your site. This should be clickable then it should list the pages they are on and if you want to delete them.