SELECT RAW ARRAY_DISTINCT(ARRAY_FLATTEN(ARRAY_AGG(doc.beers[*].name),2))
FROM bucket doc
WHERE doc.type = "brewer";
OR
SELECT RAW ARRAY_DISTINCT(ARRAY_FLATTEN( (SELECT RAW doc.beers[*].name
FROM bucket doc
WHERE doc.type = "brewer"),2));
OR
SELECT DISTINCT RAW b.name
FROM bucket doc
UNNEST doc.beers AS b
WHERE doc.type = "brewer";