src/Laravel/StorageStructure.php
public function groupFieldExist($blockName, $groupName, $fieldName)
    {
        $groups_conf = $this->getGroupsFlatConfig($blockName);

        if(!array_key_exists($groupName, $groups_conf))
        {
            return false;
        }else{
            $struct = $this->getGroupFieldsFlat($blockName, $groupName);

            return in_array($fieldName, $struct);
        }
    }
public function groupFieldExist($blockName, $groupName, $fieldName)
    {
        $groups_conf = $this->getGroupsFlatConfig($blockName);

        if(!array_key_exists($groupName, $groups_conf))
        {
            return false;
        }else{
            $struct = $this->getGroupFieldsFlat($blockName, $groupName);

            return in_array($fieldName, $struct);
        }
    }
@param string $blockName

@param string $groupName

@param string $fieldName

@return bool