class ActiveAdmin::ResourceCollection

def find_resource(obj)

Finds a resource based on the resource name, resource class, or base class. 
def find_resource(obj)
  resources.detect do |r|
    r.resource_name.to_s == obj.to_s
  end || resources.detect do |r|
    r.resource_class.to_s == obj.to_s
  end ||
  if obj.respond_to? :base_class
    resources.detect { |r| r.resource_class.to_s == obj.base_class.to_s }
  end
end