RestConnectorMasterTable:
SQL SELECT 
  "id", 
  "name",
  "__KEY_root", 
  (SELECT 
    "@Value",
    "__FK_domains" 
  FROM "domains" FK "__FK_domains" ArrayValueAlias "@Value")
FROM JSON (wrap on) "root" PK "__KEY_root"
WITH CONNECTION(Url "https://********");

[domains]:
LOAD 
  [@Value],
  [__FK_domains] AS [__KEY_root] 
RESIDENT RestConnectorMasterTable
WHERE NOT IsNull([__FK_domains]);

// Add "id" and remove __KEY_root: <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
LEFT JOIN([domains])
LOAD
  [id],
  [__KEY_root]
RESIDENT RestConnectorMasterTable;
WHERE NOT IsNull([__KEY_root]);

DROP field [__KEY_root] FROM [domains];

[root]: // Removed [__KEY_root] <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
LOAD 
  [id],
  [name]
RESIDENT RestConnectorMasterTable
WHERE NOT IsNull([__KEY_root]);

DROP TABLE RestConnectorMasterTable;