Multi-select device groups for Reference Cluster in Device Scope

Device Scope configuration for Reference Cluster currently allows selection of only a single device group at a time, requiring administrators to consolidate devices into a new combined group when multiple groups need to be referenced together. This enhancement would allow multiple device groups to be selected simultaneously when defining a Reference Cluster scope. Customers managing devices across several logical groupings would benefit from reduced administrative overhead and would no longer need to create and maintain duplicate consolidated groups solely to work around the single-selection limitation.