Start Backlog Planning for Specific Items/Item Categories

In the Start Backlog Planning job, I can see parameters for Item Category and Item, but it doesn't appear possible to select multiple values.

My requirement is to run backlog planning only for a specific set of items or item categories.

Is there a way to:

• Select multiple items or item categories in a single run?
• Restrict backlog planning to a defined list of items/categories if multi-select is not supported?

Any suggestions or best practices would be appreciated.

Thanks.