Block/System/Config/Form/Field/Acl.php
public function renderCellTemplate($columnName)
    {
        if ($columnName == 'store_id' && isset($this->_columns[$columnName])) {
            $options = $this->getOptions(__('-- Select Store --'));
            $element = $this->elementFactory->create('select');
            $element->setForm(
                $this->getForm()
            )->setName(
                $this->_getCellInputElementName($columnName)
            )->setHtmlId(
                $this->_getCellInputElementId('<%- _id %>', $columnName)
            )->setValues(
                $options
            );
            return str_replace("\n", '', $element->getElementHtml());
        }

        return parent::renderCellTemplate($columnName);
    }
public function renderCellTemplate($columnName)
    {
        if ($columnName == 'store_id' && isset($this->_columns[$columnName])) {
            $options = $this->getOptions(__('-- Select Store --'));
            $element = $this->elementFactory->create('select');
            $element->setForm(
                $this->getForm()
            )->setName(
                $this->_getCellInputElementName($columnName)
            )->setHtmlId(
                $this->_getCellInputElementId('<%- _id %>', $columnName)
            )->setValues(
                $options
            );
            return str_replace("\n", '', $element->getElementHtml());
        }

        return parent::renderCellTemplate($columnName);
    }
Render array cell for prototypeJS template

@param string $columnName
@return mixed|string
@throws \Exception