Oftentimes employment data comes in after the Constituent has been established. You can import a business relationship via Constituent Update Batch but you cannot import values for the employment history such as Job Title, Department, etc.
It is not currently possible to update the constituents job title or start date via a Constituent Update Batch or via Relationship Batch. Here is an Idea Bank Suggestion for this functionality: https://bbcrm.ideas.aha.io/ideas/CRM-I-1604
It may be possible to add the job title, employer update, and start date functionality via a customization. If this is something you are interested in, please follow-up with your Account Executive for more information.
Steps to Duplicate
1) Navigate to the batch entry functional area 2) Create a Constituent Update Batch 3) Notice that batch does not allow users to update an existing employer or job title.