How should the system administrator configure the account to provide specific users the ability to...

Create each user in both BUs > Map the same CRM username > Guide those users to find assets by navigating across BUs using the business unit switcher in the Marketing Cloud Account Engagement Classic App

Create each user in a single BU > Create an asset with the exact same name in each BU > Ensure the users have access to one of the assets that share names across BUs

Create each user in both BUs > Map the same CRM username > Guide those users to find assets by

navigating across BUs using the business unit switcher in the Marketing Cloud Account Engagement Lightning App

Create each user in a single BU > Create a folder with the exact same name > Associate assets that are needed across regions to the folders that share names across BUs