Hello,
Unfortunately, there is no easy way to create such a business unit. The thing is that Adaxes attributes (their names start with adm-) cannot be used in search queries. Also, you will need to not only create a separate membership rule in the business unit for each owner, but also clear the list each time. Considering the above, the script and the business unit will simply be useless.
Could you, please, describe where/how you want to use the business unit? Maybe we will be able to suggest an easier and simpler solution.