ARRAY_FLATTEN
Flattens nested arrays, converting them into a single-level array.
Syntax
ARRAY_FLATTEN( <array> )
Examples
SELECT ARRAY_FLATTEN([[1,2], [3,4,5]]);
┌────────────────────────────────────┐
│ array_flatten([[1, 2], [3, 4, 5]]) │
├────────────────────────────────────┤
│ [1,2,3,4,5] │
└────────────────────────────────────┘