If this option is selected, the context of grouping is the polling group name. One instance of the PerlScript is invoked for each member in the same polling group.
In case of the MA_SSH_LOGIN_CHECK example, PerlScript is invoked for every member of the group. If the polling group has 10 members, 10 instances of PerlScripts are invoked.
This option is beneficial in cases where you have to monitor multiple objects with common network connections. For example, if you have to monitor a SQL database table, each check reports different tables of the common database.