DROP TABLE IF EXISTS TEMP.test_version_nested
CREATE TABLE TEMP.test_version_nested (
    object_id UInt8,
    names Nested (
        date Date,
        name String
    )
) ENGINE = Memory

INSERT INTO TEMP.test_version_nested VALUES (1, [today()], ['one'])

CREATE MATERIALIZED VIEW TEMP.test_version_nested_m 
ENGINE = AggregatingMergeTree(names.date, (object_id), 8192) 
AS SELECT object_id, names.date from TEMP.test_version_nested

Received exception from server:
Code: 169. DB::Exception: Received from localhost:9000, ::1. DB::Exception: Date column (names.date) for storage of MergeTree family must have type Date. Provided column of type Array(Date). You may have separate column with type Array(Date)..

INSERT INTO TEMP.test_version_nested 
VALUES (1, [today()], ['two'])

Received exception from server:
Code: 60. DB::Exception: Received from localhost:9000, ::1. DB::Exception: Table TEMP.test_version_nested_m doesn't exist..

CREATE MATERIALIZED VIEW TEMP.test_version_nested_m AS
select 1 from TEMP.test_version_nested
DROP TABLE TEMP.test_version_nested_m