kubernetes: Cannot sort multiple kinds with kubectl get

What happened:

I am able to kubectl get two kinds at once by separating them with comma: kubectl get cm,secret

However, I get an error when I try to do the same with sorting: --sort-by='{.metadata.name}'

What you expected to happen:

I expected the same objects returned in sorted order.

How to reproduce it (as minimally and precisely as possible):

1. Create some objects in a namespace:

   kubectl create ns sort
   kubectl -n sort create cm one
   kubectl -n sort create cm two
   kubectl -n sort create secret generic three
   kubectl -n sort create secret generic four
   

2. View them together as a table:

   $ kubectl -n sort get cm,secret
   NAME            DATA   AGE
   configmap/one   0      2m31s
   configmap/two   0      2m28s
   
   NAME                         TYPE                                  DATA   AGE
   secret/default-token-cnw58   kubernetes.io/service-account-token   3      3m25s
   secret/three                 Opaque                                0      2m21s
   secret/four                  Opaque                                0      2m17s
   

3. View them separately with sorting:

   $ kubectl -n sort get cm --sort-by='{.metadata.name}'
   NAME   DATA   AGE
   one    0      58s
   two    0      55s
   
   $ kubectl -n sort get secret --sort-by='{.metadata.name}'
   NAME                  TYPE                                  DATA   AGE
   default-token-cnw58   kubernetes.io/service-account-token   3      116s
   four                  Opaque                                0      48s
   three                 Opaque                                0      52s
   

4. Get an error when trying to view them together with sorting:

   $ kubectl -n sort get cm,secret --sort-by='{.metadata.name}'
   error: couldn't find any field with path "{.metadata.name}" in the list of objects
   

Environment:

• Kubernetes version (use kubectl version):

  Client Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.0", GitCommit:"c2b5237ccd9c0f1d600d3072634ca66cefdf272f", GitTreeState:"clean", BuildDate:"2021-08-04T17:56:19Z", GoVersion:"go1.16.6", Compiler:"gc", Platform:"darwin/amd64"}
  Server Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.3+k3s1", GitCommit:"1d1f220fbee9cdeb5416b76b707dde8c231121f2", GitTreeState:"clean", BuildDate:"2021-07-22T20:52:14Z", GoVersion:"go1.16.6", Compiler:"gc", Platform:"linux/amd64"}
  

• Install tools: k3d, brew install kubernetes-cli