Do man snmp_config
:
INCLUDING OTHER CONFIGURATION FILES
It is possible to include other configuration files for processing
during normal configuration file processing.:
# include site specific config
includeFile site.conf
This will load the specified configuration file. The
path to file must be either absolute, starting with '/',
or relative. The relative path is then relative to the directory
where the parent file with 'includeFile' directive resides.
The included file name does not need to have '.conf' suffix.
# include a all *.conf files in a directory
includeDir /etc/snmp/config.d
This will search specified directory for all files with '.conf'
suffix and process them as if they were included using includeFile
directive. The configuration files are not processed in any particular
order.
The specified directory must be absolute directory path.