The first one should do the trick [Module.Object_AssociatedObject = $AssociatedObject] will retrieve all objects that have an association to $AssociatedObject.
Edit: Because it is a java action you call it needs to be full xpath, so use something like.
'//PipsAndSubbies.Job[PipsAndSubbies.Job_JobFile/PipsAndSubbies.JobFile/name = '+$JobFile/name'+']'
Also because you cannot select the actual mendix id within mendix and mendix will not allow you to set an object inside a string you cannot compare the object to an variable. Rather you should have a unique attribute that can be used to retrieve your JobFile.