We need to be able to filter event participants by the constituent lists from which they were imported into the event (i.e., the constituent lists created under the Lists tab of NXT).

This (alongside deleting multiple participants at once) would allow for deleting lists that were accidentally added to an event or should no longer be included in the event.

With this functionality, we would be able to filter, select, and work with participants based on the constituent lists they came from as well as delete all participants imported from accidentally added (or no longer wanted) constituent lists.