Hi,

You can use 'List collector' type for catalog item/record producer variable.

List collector variables are a great way (currently the only way) to allow a user to select multiple options from a referenced table in a single variable on a service catalog item. The list collector variable allows you to choose from one to many (potentially hundreds or more) selections.

And for 'List' type field on tables.

List is a reference field that accepts multiple references rather than just one.

If I have answered your question, please mark my response as correct and/or helpful.

Thanks,

Suseela P.