Using this code
$chooser = $this->_layout->createBlock('\Magento\Catalog\Block\Adminhtml\Product\Widget\Chooser');
var_dump(get_class_methods($chooser));
$configChooser = [
'button' => [
'open' => __('Select Products'),
'type' => '\Magento\Catalog\Block\Adminhtml\Product\Widget\Chooser',
]
];
$chooser->setConfig($configChooser)
->setFieldsetId($fieldsetData->getId())
->prepareElementHtml($productChooser);
I can get a pretty nice product selector for my custom field in my custom form, but i need it to be able to select several product. There is a chooser config that i can be able to set?