Meraki AutoVPN can be setup as Hub and Spoke or as Full Mesh.
It's as easy as selecting the option when setting up AutoVPN in the dashboard.
For full mesh, every node is configured as a hub.
For hub and spoke, you specify your hubs and your spokes.
Of course there as multiple differences, pro's and con's for each topology.
The following doc provides a lot of info around this.
Meraki SD-WAN - Cisco Meraki Documentation