Including a multiple select field in my module using an array of data

You can add a multiple select field to your form by defining its properties and also including the field in your list of add or edit fields.

Here's a sample code to include a multiple select field to your form by defining an array of the data you want to include;  

 
$objConfig->multipleSelect('field_name', 'field_label', $required = 0)
$objConfig->childArray('data');