how to restart only certain processes using supervisorctl?

Since supervisorctl accepts multiple processes on the command line, you can take advantage of shell brace expansion (e.g. in Bash) to control multiple processes:

supervisorctl restart process{1..4}

is expanded by the shell into

supervisorctl restart process1 process2 process3 process4

as if you had typed that out explicitly.

supervisord supports process groups. You can group processes into named groups and manage them collectively.

[unix_http_server]
file=%(here)s/supervisor.sock

[supervisord]
logfile=supervisord.log
pidfile=supervisord.pid

[program:cat1]
command=cat

[program:cat2]
command=cat

[program:cat3]
command=cat

[group:foo]
programs=cat1,cat3

[supervisorctl]
serverurl=unix://%(here)s/supervisor.sock

[rpcinterface:supervisor]
supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface

supervisorctl command can be called with a group name:

supervisorctl restart foo:

as well as with multiple process names:

supervisorctl restart foo:cat1 cat2