How to get Calendar Ids of a group?

Yeah Got it! Thanks @Ben

And this will be the code if the group has subgroups.

#set($groupVar = $core_v2_group.Current)
#set ( $subgroupVar = $core_v2_group.List("%{ IncludeAllSubGroups = 'true',ParentGroupId = $groupVar.Id }") )
#foreach($calendar in $calendar_v1_calendars.List("%{PageSize=50,CalendarContext='Group',CalendarReferenceId=$subgroupVar.Id}")
#each
    <li>$calendar.Id</li>
#nodata
    <li>No calendars exist in the current group.</li>

#end