How to divid result set window into N tiles and return the tile position using the NTILE() function?

NTILE(n) is a MySQL built-in window function that divides result set window into n tiles and returns the tile position of the current row. For example:

SELECT help_topic_id AS tip, help_category_id AS cid,
  NTILE(5) OVER w, ROW_NUMBER() OVER W, COUNT(*) OVER W
  FROM mysql.help_topic
  WINDOW w AS (PARTITION BY help_category_id);
  -- +-----+-----+-----------------+---------------------+-----------------+
  -- | tip | cid | NTILE(5) OVER w | ROW_NUMBER() OVER W | COUNT(*) OVER W |
  -- +-----+-----+-----------------+---------------------+-----------------+
  -- |   0 |   1 |               1 |                   1 |               2 |
  -- |   1 |   1 |               2 |                   2 |               2 |
  -- |   2 |   2 |               1 |                   1 |              35 |
  -- |   6 |   2 |               1 |                   2 |              35 |
  -- |   7 |   2 |               1 |                   3 |              35 |
  -- |   8 |   2 |               1 |                   4 |              35 |
  -- |   9 |   2 |               1 |                   5 |              35 |
  -- |  10 |   2 |               1 |                   6 |              35 |
  -- |  11 |   2 |               1 |                   7 |              35 |
  -- |  12 |   2 |               2 |                   8 |              35 |
  -- |  13 |   2 |               2 |                   9 |              35 |
  -- ...
  -- +-----+-----+-----------------+---------------------+-----------------+

Reference information of the NTILE() function:

NTILE(n): pos
  Divides result set window into n tiles and returns the tile position
  of the current row.

Arguments, return value and availability:
  n: Required. The number of tiles to be divided into.
  pos: Return value. The position of the current tile.
  Available since MySQL 8.

⇒ PERCENT_RANK() - Rank Percentage of Sorted Values

⇐ NTH_VALUE() - N-th Value of Result Set Window

⇑ MySQL Functions on Result Set Windows

⇑⇑ MySQL Function References