Out of the box, no. However, if I recall correctly, there are a couple options. When you use the ##Category## variable, App Portal converts the list of categories for the catalog item into a comma-separated list (if there is more than one category selected for the catalog item). The ServiceNow API requires that all fields are sent as text strings. So, option #1 is to create a transform script that reads the comma-separated list and adds all the individual categories to the catalog item. Option #2 is a bit easier, but I don't remember exactly how to configure it. I believe you just change the field type of the category field in the catalog item table in ServiceNow to a multi-valued text field instead of a single text field. Then ServiceNow will automatically parse the comma-separated list for you. Your ServiceNow developers could likely instruct you on the best way to achieve this.
Anything expressed here is my own view and not necessarily that of my employer, Flexera. If my reply answers a question you have raised, please click "ACCEPT AS SOLUTION".
