/usr/lib/python2.7/dist-packages/slapos/grid/templates/group_partition_supervisord.conf.in is in slapos-node-unofficial 1.3.18-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | [group:%(instance_id)s]
programs=%(program_list)s
|