Customfields: 'Select All' from dropdown list

[EsSa55]

Hello

I understand this could be a Joomla 3 issue so posting is also in Joomla Forum.

In Joomla 2/Virtuemart 2, I have a number of vm customfields with a long list of selection options.

As you can see from the screenshot, in Joomla 2 there is the 'Select All' feature.

Unfortunately, this is not included in Joomla 3 and I wonder if anyone can advise as to how to include it as adding each option individually is extremely time-consuming and try to do it via csv import to db involves a number of tables.

TIA