Hi @jarvis
You can first get all the sectors by performing a get_posts – http://codex.wordpress.org/Template_Tags/get_posts
Loop over these results, and for each sector display the title and link.
To find the count of jobs in this sector will require another get_posts call for each sector.
The post_object (multi-select) saves it’s data in the same format of a relationship field (serialized array of IDs), so you can follow this tutorial to perform a backwards query: http://www.advancedcustomfields.com/resources/tutorials/querying-relationship-fields/
Thanks
E
