Exotic groupoid C^*-algebras associated to double groupoids

We consider a class of local action groupoids called double groupoids which are constructed from pairs of subgroups satisfying similar conditions to those of a matched pair of groups. They are partial transformation groupoids whenever they are \'etale, and in this setting, we show that if the partially acting group admit exotic ideal completions in the sense of Brown and Guentner, then the corresponding double groupoid also admit exotic C^*-completions.