Final query

final_query.sql

with annotated_data as (
  SELECT
    *,
    to_json(struct(* except (object_id, sample_id))) as xxx,
    lag(to_json(struct(* except (object_id, sample_id)))) over tracked_id_timeline as prev_xxx,
    row_number() over tracked_id_timeline as rr
  FROM
    VALUES ('A1', 2, 1, 5), ('A1', 1, 1, 5), ('A2', 3, 3, 7), ('A1', 3, 2, 6) tab
      (object_id, sample_id, feature_1, feature_2)
  WINDOW tracked_id_timeline as (PARTITION BY object_id ORDER BY sample_id)
)
select
  * except (rr, prev_xxx, xxx)
from
  annotated_data
where
  rr = 1 or xxx != prev_xxx