Ok so here is a quick scenario. Global teams for Global locations. In those teams are channels for various Depts. Obviously not each Dept needs to see the others channel.. Is there any plan for restricting channels to certain users within the same team?
@WelshViking I would recommend creating Teams for each department, and then a larger or potentially Org-wide team for your global teams. Teams works really well when people are in multiple teams, it's not the intended design for their to be just one.
@adam deltinger is right that there is a feature coming, but this is more for where there's a busy team but then one channel needs to have a more restricted membership, for example a management team that is only available to a small number of people. It's not intended for the purpose you describe, and also won't be available for some time.