The phrase "latter group" refers to the second group or the group mentioned last in a discussion, compared to a previous group or groups mentioned earlier. Full definition
The latter group has received money from foundations controlled by the Koch brothers, whose company owns refineries and more than 4,000 miles of oil and gas pipelines. (fortune.com)
If you fall in the latter group, and you're a business owner, you can't cut yourself off from messy reality — your business requires you to stay plugged in. (inc.com)
The reason is that this latter group may be subject to more frequent reviews by the public in relation to their work. (inc.com)