Yes. GMM supports a three tier hierarchy. Service Provider --> Account --> Customer
Can use this hierarchy as administrative domains to manage the gateways and separate it into as you say continent, country and city. If administrative domains are not required, another way is to use our Custom Fields to label gateways within an organization. A gateway may have multiple labels.
Accounts are created as SP, Account or Customer per situation. For example a customer may want to be at SP level or they are fine with being under our partner SP organization as the partner is managing their gateways.
