A group can now hold up to three options side by side - for example Color, Style, and Material - each rendered as a separate swatch row on the product page. Previously this layout required stitching together multiple linked groups; now it lives inside one group.
When a shopper picks a swatch in the first row, the second and third narrow to show only combinations that exist for that selection. Each product in the group needs a swatch on every option.
Automations support multiple options too, so groups created from collections or metafields can use the same multi-row layout.
See Multi-option groups for setup details. Available on the Advanced plan or higher.