Select multiple values from dropdown list in Web UI Newhire form

Hi,

We have a requirement to provide an option to end user to select multiple products from a dropdown list in WEB UI New hire form.

with OTB option available, we are able to make user select one product from dropdown, but any leads how to make multiple products selected from drop down,

We are using version 7.1.3 currently.

Thanks in Advance.

Regards,

Rohit