SET @path = '/path/to/images/12345.png';

SELECT
	( @path ) AS path,
	SUBSTRING_INDEX( @path, '/', -1 ) AS segment_negative_1,
	SUBSTRING_INDEX( @path, '/', -2 ) AS segment_negative_2,
	SUBSTRING_INDEX( @path, '/', -3 ) AS segment_negative_3,
	SUBSTRING_INDEX( @path, '/', -4 ) AS segment_negative_4,
	SUBSTRING_INDEX( @path, '/', -5 ) AS segment_negative_5
;