Hi Glen,

I haven't come across an implementation splitting data out in this way. Outside of setting up an entirely separate Totara site for that subsidiary, I suspect it would require custom code and database work to enforce a subset of the data only being maintained on one set of servers.  

My recommendation is to discuss this situation with a Totara Partner in your region, who can consult on and customize an implementation to meet those needs. https://www.totaralms.com/partners

Thanks!