This is an overview to use a filter formula to compare to columns to see if someone is added in a new roster but not included in the prior version. This will allow you to pull out any unique net new adds that were not in the prior version.
=FILTER(Column 1 Range, NOT(COUNTIF(Column 2 Range, Column 1 Range)))
Use Case: List one is a new roster provided by the client that shows an export from their workday system with the master roster. List 2 is the ACC Org report unique IDs we have in Accelerate for the users currently enrolled. Using the FILTER formula with NOT and COUNTIF allows you the ability to review the lists and populate anyone from list 1 that is not previously on list 2 (i.e. a net new user to add).