It would be nice if Zabbix agent and server set custom process names for its childs. For example this is grep of 'ps aux' for nginx:

root 2436 0.0 0.0 78644 1516 ? Ss Jun20 0:00 nginx: master process /usr/sbin/nginx
www-data 2439 0.0 0.0 79712 4064 ? S Jun20 0:25 nginx: worker process
www-data 2441 0.0 0.0 79648 3980 ? S Jun20 0:24 nginx: worker process
www-data 2442 0.0 0.0 79628 3996 ? S Jun20 0:24 nginx: worker process
www-data 2443 0.0 0.0 79620 4048 ? S Jun20 0:28 nginx: worker process

For more details how to archive this see man prctl(2)http://man7.org/linux/man-pages/man2/prctl.2.html, PR_SET_NAME option.