Issue with Organization security profile while creation Job requisitions.

There is a business requirement in which user should be able to access business unit only from which belongs while creating the Job requisition. For example - if user is from A1 business unit he should be able to see only A1 business unit in the dropdown while creating job requisitions.

Since Organization security profile controls business unit LOV for job requisitions. We have created custom Organization security profile secured by Organization hierarchy - Tree Structure (Organization hierarchy), Top Organization, Specific Organization but it is still providing all the business units in the LOV. Tree structure contain top node as Enterprise then business units as child nodes.