Select one or more groups. > Group menu > Explode
The Explode command ungroups all objects in a group, regardless of the number of nested groups, unlike Ungroup, which ungroups one level only.
As with the Ungroup command, all exploded entities remain in the current selection set.
Warning: Ungroup and Explode remove all transform animations that have been applied to the group as a whole. As with the Ungroup command, all exploded entities remain in the current selection set.