Group by more than one field in Group Tags in a Word-Based Gen Template

Hi,

Refer Group Tags in a Word-Based Gen Template. For example:

<# <Group Select ="/Opportunity//OpportunityLineItems" By="./Category" />

<# <Content Select="./GroupName" Optional="true"/> #>

<# <EndGroup/> #>

Is it possible to group by more than one field? For example, group by Category and Service rather than just Category?

If yes, what would the correct syntax be?

If no, are there other options?

Thanks.