my $flow_id = $data{partners}{$part_id}{flow}; for my $wfref (@{$data{flows}{$flow_id}}) { #... } #### my $partner = $data{partners}; my $flow_id = $partner->{$part_id}{flow}; my $flows_ref = $data{flows}{$flow_id}}; for my $wfref (@$flows_ref) { #... } #### my $flow_id = $data{partners}{$part_id}{flow}; my $flows_ref = $data{flows}{$flow_id}}; for my $wfref (@$flows_ref) { #... } #### Change %{$data{flows }} to just %flows. Change %{$data{partners}} to just %partners.