src/Laravel/StorageStructure.php
public function subGroupExist($blockName, $groupName, $subGroupName)
    {
        $groups_conf = $this->getGroupsSub9n($blockName);

        if (array_key_exists($groupName, $groups_conf))
        {
            return in_array($subGroupName, $groups_conf[$groupName]);

        }else{

            return false;
        }
    }
public function subGroupExist($blockName, $groupName, $subGroupName)
    {
        $groups_conf = $this->getGroupsSub9n($blockName);

        if (array_key_exists($groupName, $groups_conf))
        {
            return in_array($subGroupName, $groups_conf[$groupName]);

        }else{

            return false;
        }
    }
@param string $blockName

@param string $groupName

@param string $subGroupName

@return bool