It is not currently possible to change the ownership of multiple queries in bulk from the front end of the application. Here is an Idea Bank Suggestion for this functionality: https://bbcrm.ideas.aha.io/ideas/CRM-I-2304
It may be possible to mass update the queries owner via an Update script from the back end of the application. Your developer would need to create an Update script to change the owner on the specific Ad-hoc queries in the Ad-hoc query table. If this is something you are interested in, please reach out to your Developers or your SDK contact for more information.