Clickhouse version 21.10.6.2,21.10.5.3 and lower:
```
CREATE TABLE repro (
`id` UInt64,
`version` UInt16,
`conversations.id` Array(UInt64),
`conversations.routings.id` Array(Array(UInt64))
)
ENGINE = ReplacingMergeTree(version)
ORDER BY (id)
SETTINGS min_bytes_for_wide_part = 0, min_rows_for_wide_part = 0;

INSERT INTO repro (`id`, `version`, `conversations.id`, `conversations.routings.id`)
VALUES (1, 1, [1], [[1]]);

select * from repro;

┌─id─┬─version─┬─conversations.id─┬─conversations.routings.id─┐
│  1 │       1 │ [1]              │ [[1]]                     │
└────┴─────────┴──────────────────┴───────────────────────────┘

```
CH version: 21.11.2.2 and upper:

```
CREATE TABLE repro (
`id` UInt64,
`version` UInt16,
`conversations.id` Array(UInt64),
`conversations.routings.id` Array(Array(UInt64))
)
ENGINE = ReplacingMergeTree(version)
ORDER BY (id)
SETTINGS min_bytes_for_wide_part = 0, min_rows_for_wide_part = 0;

INSERT INTO repro (`id`, `version`, `conversations.id`, `conversations.routings.id`)
VALUES (1, 1, [1], [[1]]);

select * from repro;

Received exception from server (version 21.11.2):                        <------------- unexpected, it should have results.
Code: 44. DB::Exception: Received from localhost:9000. DB::Exception: There is no subcolumn routings.id in type Nested(id UInt64, `routings.id` Array(UInt64)): While executing MergeTreeInOrder. (ILLEGAL_COLUMN)

```

**Unexpected Behaviour:**
It should not have an exception in the select query.



{
    if (column.isSparse())
        return Kind::SPARSE;
    return Kind::DEFAULT;
}
String ISerialization::kindToString(Kind kind)
{
    switch (kind)
    {
        case Kind::DEFAULT:
            return "Default";
        case Kind::SPARSE:
            return "Sparse";
    }
    __builtin_unreachable();
}
ISerialization::Kind ISerialization::stringToKind(const String & str)
{
    if (str == "Default")
        return Kind::DEFAULT;
    else if (str == "Sparse")
        return Kind::SPARSE;
    else
        throw Exception(ErrorCodes::LOGICAL_ERROR, "Unknown serialization kind '{}'", str);
}
String ISerialization::Substream::toString() const