Variations slicing allows specification of a facet name or group ID by which variations of an item should be split into individual result items in the Autocomplete, Search, or Browse responses. Only one facet name or group ID is allowed.
If a variation slicing rule is applicable, the affected Search, Autocomplete, or Browse response may contain multiple results (in response.results) with the same item ID (data.id).
When creating variation slicing rules, it is advised that you use facets which only have 1 unique value per variation. Otherwise, the same variation may end up being used to represent two or more different result tiles in product listing pages, resulting in identical results.
For example, if splitting results by color, one would expect one result tile per color. If the same variation has both color: blue and color: green, it may end up being used as face-out variation in 2 different result tiles, each representing one of the colors (recall that variations also inherit all the facets of their parent item). In such cases, if it's desirable for the multi-colored variation to form a third group, which represents the combination of both colors, it is advised that a new color facet is assigned to the multi-colored variation, such as "color": "blue/green".