Can I config logstash to read config other than the path /etc/logstash/conf.d/

I am trying to set the path for different config as below,
pipeline.yml:
- pipeline.id: main
path.config: "/etc/logstash/conf.d/*.conf"
- pipeline.id: dhcp-test
path.config: "/home/elk2/dhcp_log.conf"
- pipeline.id: portfolio-test
path.config: "/home/elk/logstash.conf"
but the log told me
[2019-07-22T10:54:21,177][INFO ][logstash.config.source.local.configpathloader] No config files found in path {:path=>"/home/elk2/dhcp_log.conf"}
[2019-07-22T10:54:21,182][INFO ][logstash.config.source.local.configpathloader] No config files found in path {:path=>"/home/elk/logstash.conf"}

Either that file does not exist or logstash does not have permission to read it.