A stepping stone model with site space a continuous, hierarchical group is constructed via duality with a system of (delayed) coalescing ``stable'' L\'evy processes. This model can be understood as a continuum limit of discrete state-space, two allele, genetics models with hierarchically structured resampling and migration. The existence of a process rescaling limit on suitable large space and time scales is established and interpreted in terms of the dynamics of cluster formation. This paper was inspired by recent work of Klenke.