Option 1: Why not just recreating this list of contacts in Sales Navigator from scratch, and applying the “posted on LI in the last 30 days”? This would be the best option provided you’re not using a filter in Apollo that Sales Navigator doesn’t have, and/or if the list is less than 2500 people (as you’d be caped to extract that much from sales navigator)
Option 2: As Mike said, you could export the list from Apollo with a scraper, then enrich these contacts to extract the linkedin posts they wrote (possible with Airscale, and I believe with Clay too)
Once you have a column containing these posts, I’d simply run an AI prompt to tell you whether this person wrote a post in the last 30 days.
Here’s an example of the output for option #2:
