There should be no apostrophe because what you mean is that the decision belongs to the group.

VOA: special.2010.02.11

It was a phenomenal thing, and she ended up on this very famous French television show called Apostrophe, with Bernard Pivot, who said that she was one of the most interesting people that he'd ever had on his show. And she died in 1977.

真的很了不起,她最后和伯纳德·皮沃特一起上了一个,法国著名的电视节目,叫"省略号",他说她是上这个节目的最有趣的人之一,她最后死于1977年

耶鲁公开课 - 1871年后的法国课程节选

People often add an apostrophe to "its" in a sentence like "The group made its decision."

VOA: special.2010.02.11

"It's" with an apostrophe is short for "it is," as in "It's raining."

VOA: special.2010.02.11