So Foreign Affairs and International Development did not have a third vice-chair position in the previous session. It was only the Special Committee on Canada-China Relations that had that position, and that was done by motion from the House forming the special committee. The Standing Orders do not allow for a third vice-chair.
There was a report from the Standing Committee on Procedure and House Affairs in the last session. That report was never concurred in, so currently there is no mechanism by which standing committees can elect a third vice-chair.