AFAIK there is some tool to extract the single missions from a campaign.
(Link?! :( )
Then you would need to open that mission in the Editor and check the goals. IIRC that is the "crosshair"-button on the left side. It should show the goals. For a better first overview, switch to "List"-View of the goals.
You can click the single goals (either DESTROY/SURVIVE-type) and click "Show". That should select the group connected with that goal.
Mhmm.. hope I wrote no nonsense .. can not check - have no LockOn under Linux ;)