it works over your small data set. not sure if you can get rid of the distinct with so many columns you are grouping by.

here is the solution:

WITH RN AS (SELECT ROW_NUMBER () OVER (ORDER BY pms_id) RN1,

ROW_NUMBER() OVER (PARTITION BY eq_id,bl_id,fl_id,rm_id ORDER BY pms_id) RN2,

*

FROM #mytable)

SELECT DISTINCT RN1 - RN2 OrderColumn, eq_id,bl_id,fl_id,rm_id,

REPLACE(STUFF((SELECT ', ' + instructions

FROM RN i

WHERE i.RN1 - RN2 = o.RN1 - o.RN2

FOR XML PATH('')),1,2,''),',',' &')

FROM RN o

ORDER BY RN1 - RN2

if you do not care about the order you can omit the OrderColumn from the result set and remove the order by clause

EDIT: Thanks for the DDL and Sample data on your first post.

EDIT2: Explaining the code:

the first CTE gives us 2 row numbers we can subtract and the result of the math stays the same over the different groups.

the select statement selects our grouping id and then using FOR XML PATH concantenates the instructions together along with a ,. i use a , because it will stay the same in the conversion to XML and then finally the replace changes the , to the requested &