DMVPN dual hub dual cloud
A DMVPN dual hub duel cloud topology delivers redundancy by allowing two hubs. Unlike the DMVPN dual hub single cloud option, the dual cloud option uses two DMVPN networks which means that all spoke routers will get a second multipoint GRE interface.
It is considered best practice to employ the dual hub dual cloud over the dual hub single cloud DMVPN solution in production networks.
Links:
https://forum.networklessons.com/t/dmvpn-dual-hub-single-cloud/1328/49?u=lagapides
https://networklessons.com/cisco/ccie-enterprise-infrastructure/dmvpn-dual-hub-dual-cloud