Liaison EMP

We want to be able to isolate a group of people imported in one import, without having to create a different source bucket every time. Also we thought that by importing with a Note file, we would be able to search on the contents of the Notes, where we often put a recruiting event where we collected paper information slips. Please let us know if there is an efficient way of later seeing people imported in a specific set, or if there are suggested best practices for searching on key information on students. Thanks!