I thought I'd post an update as the top answers are quite old now and there are better ways to do this - especially for multiple groups, so hopefully someone stumbling across this old question will find my post useful...
N.B. Your update set should be created in the Global scope.
Option 1: Download the Add to Update Set plugin
This adds an option to force transactional data to update sets:
The latest version also includes any 'related' data, so for groups, it will include the main sys_user_group record, but also add the dependant records from related tables (user memberships, roles, skills, and group types).
Warning: I've found that this bogs down at more than 25 groups, so if you've created a large number of new groups, Option 3 (force to update from a background script) may well be quicker and certainly less likely to crash your connection. This is because it exports all the related table records, which can also require time to remove unnecessary records e.g. group roles from the Update Set.
DIY
For the below options, ensure you capture all the data you need as group records exist across a few tables:
Main table
sys_user_group
Dependent tables
sys_user_grmember (group's members)
sys_user_group_type (group type)
sys_group_has_skill (group skills)
sys_group_has_role (group roles)
N.B. You may not want to export all of these tables - for instance, skills and roles are often inherited rather than granted directly.
Option 2: Export XML (as suggested)
If for some reason you can't install the plugin (it's really useful generally) and only have a few groups to do, you can export the XML from the group record:
You can then export go to the corresponding tables on the environment to import into, right click on a column header and 'import xml', ensuring you import to the sys_user_group table first.
Option 3: Force to update set from a background script
You can force to update set via a background script (rather than using the plugin from Option 1). The information is here courtesy of SN Guru.
Of course, instead of using .get, you can use a query with a while loop to add multiple groups' records from the tables you need e.g.
var um = new GlideUpdateManager2();
//Query for the record
var rec = new GlideRecord('sys_user_group');
rec.addEncodedQuery('[YOURENCODEDQUREY]') //right click on a list filter to copy query
rec.query();
while(rec.next(){
//Push the record into the current update set
um.saveRecord(rec);
}
Versus the Plugin, this has the advantage of not adding records to your update set which aren't needed and it can be quicker for 20 groups or more
