You can extract subscribers by activity check targeting by following below:

The activity ID you choose must have had an activity check run on it previously. The resulting file contains a record for every subscriber that was targeted in the check, including ID, external ID, email, phone, and a column for each segment in the activity indicating which subscribers match which segments.

1. Find the activity by searching for the activity ID or name in the Global Search or via Campaigns.

   • Click the options menu ("...") located on the bottom right corner of the Activity tile and select the 'Extract Recipients' link.
     This will bring up the subscriber extract window.

2. Under 'Extract type', select 'Activity check targeting'.
3. Enter the activity ID that you want to extract subscribers from.
4. Click 'Generate extract' on the bottom left.