time spent between steps while ignoring other id's steps in between

[skutovicsakos]

Hi,

I want to calculate the time spent between two steps with the same id in a new column.

What I mean, is that even though in time after doc_id 1; step_id 4 it comes doc_id 2; step_id 2, but I want to calculate the time difference between doc_id 1;step 4 and doc_id1; step 5.

every doc_id can start with a random step_id, but it is sequential after

DOC_ID	STEP_ID	START_DATE	END_DATE
1	4	1/24/2019 1:43:47 PM	1/24/2019 1:43:48 PM
2	2	1/24/2019 1:43:49 PM	1/24/2019 1:43:50 PM
1	5	1/24/2019 1:48:42 PM	1/24/2019 1:48:43 PM
2	3	1/24/2019 1:48:43 PM	1/24/2019 1:48:43 PM
3	4	1/24/2019 1:51:49 PM	1/24/2019 1:51:49 PM
2	4	1/24/2019 1:51:50 PM	1/24/2019 1:51:52 PM
1	6	1/25/2019 9:11:12 PM	1/25/2019 9:11:12 PM
3	5	1/25/2019 9:11:28 PM	1/25/2019 9:11:28 PM

[stevedep]

Like this?

_SD = 
var _doc = SELECTEDVALUE('Table'[DOC_ID];"Multiple")
var _sd = SELECTEDVALUE('Table'[START_DATE])
return
DATEDIFF(
CALCULATE(MAX('Table'[END_DATE]);FILTER(ALL('Table');'Table'[DOC_ID]=_doc && 'Table'[START_DATE] < _sd))
; MIN('Table'[START_DATE]);MINUTE)

as seen here:

File available here. 

Pls mark as solution if it works for you. Thumbs up for the effort is appreciated.

Kind regards, Steve.