You will want to use divisions for this. I know there was a "non feature" (aka bug) where the Activity Detail was not respecting division awareness. I believe that was fixed and released, but you will need to test that. Otherwise, Divisions works well for the BPO to only allow them access to their own agents and queues.
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Robert Wakefield-Carl
TTEC Digital, LLC fka Avtex Solutions, LLC
Contact Center Innovation Architect
https://www.Avtex.comhttps://RobertWC.Blogspot.com------------------------------