Stuck building subquery

SQL++
4

Thought project roles.id as user id

Try ANSI JOIN and GROUP BY

CREATE INDEX ix1 ON identity(DISTINCT `roles`, id, name) WHERE _class = "com.package.User";
SELECT d.id, d.name, ARRAY_AGG( DISTINCT {u.id, u.name}) AS managers
FROM (SELECT META(p).id, p.name, r.id AS rid
      FROM identity AS p
      UNNEST p.`roles` AS r
      WHERE p._class = "com.package.Project" AND r.name = "Manager") AS d
JOIN identity AS u ON ANY v IN u.`roles` SATISFIES v = d.rid END AND u._class = "com.package.User"
GROUP BY d.id, d.name;