Thanks for checking out our plugins!
This type of filtering is indeed possible with Filter Bar. You can see an example of how Filter Bar works over on our demo site wpshindig.com. In that example, the organizer field is set to use a dropdown, but you can also set it to use checkboxes, which would let users select multiple organizers at one time. This article has some more details on the settings that are available with Filter Bar.
Filtering works the same way for events that have been imported from Facebook (which requires Event Aggregator) as those that were created directly on the site.
We do offer full refunds within 30 days of purchase, so if you’d like to take Filter Bar and/or Event Aggregator for a test run, feel free to do so! Please let me know if you have any additional questions.