Please follow the below steps.
- Go to 'Network Admin' -> 'Content Copier' -> 'Bulk Copy/Update' OR 'Network Admin' -> 'WMCC' -> 'Bulk Copy/Update'.
- You will see WP Multisite Content Copier page.
- Select content type (posts or pages).
- Select source site you want copy/update from.
- Add number of records per page.