When you uploaded the lists, if you used the Import List feature and created 5 different static lists when you did this, then you would use the Member of List filter specifying the desired BU list you want to evaluate and using the Email Bounced filter for the email you sent. This would provide a list of emails with hard bounces in your list.
If you want to further refine the list, you can use the Email Invalid filter and/or the Email Suspended Cause filter with the "is not empty" argument and the Email Suspended At filter with the date your email was sent.
You should use a ration of hard bounce leads / total leads for each BU when you compare the lists to each other.
To send an email to multiple static lists, your smart list should use the Member of List, click the green "+", chose each of the 5 lists from the drop down list, and click OK.