Create a list of columns with value per row

[Clause9]

Subject probably makes no sense so let me explain with an example:

	A.1	A.2	A.3	A.4	A.5	A.6	A.7	A.8	DESIRED RESULT
#001	1			3	4				A.1, A.4, A.5
#002								1	A.8
#003	1	1	3			2			A.1, A.2, A.3, A.6
#004				2					A.4
#005							1		A.7
#006		3			3			3	A.2, A.5, A.8
#007			2						A.3
#008		2		1				2	A.2, A.4, A.8

The desired result illustrated in the table will probably be in another tab of the worksheet. Oh, the commas as seperators are optional

What form of lookup formula do I need to do to get the header value and how do I ensure that only cells with a value are considered? 

Thanks in advance

[#2 · Accepted solution]

@Clause9 

=BYROW(B2:I9,LAMBDA(row,TEXTJOIN(",",,FILTER(B1:I1,NOT(ISBLANK(row))))))

You can try this formula.

[#3]

@Quadruple_Pawn Vielen Dank!!!

That works perfectly - I won't pretend to follow the logic or understand what a LAMBDA function is but the formula does exactly what I asked. I've even managed to transpose it so I get the IDs per column as follows:

=BYCOL(B2:I10,LAMBDA(column,TEXTJOIN(CHAR(10),TRUE,FILTER(A2:A10,NOT(ISBLANK(column))))))

Your help is very much appreciated!

[#4]

Blast; I spoke too soon

The formula works perfectly in the example I provided however, the real use case is slightly different.

A table similar to my example is one tab of a workbook named Assessment, the IDs are in cells A7:A130, the header values are in cells L7:CZ7 so the range of cells is L7:CZ130.

Another tab named SOA contains a list of the header values in 'Assessment'!L7:CZ7 in Col A (cells A7:A95). The SOA tab contains a range of information associated with each header value in Cols B:K.

I'd like to get the IDs per header value column using the transposed formula in my last reply and insert these into a new column in the SOA tab.

I put the example formula into cell 'SOA'!L7 and it returned the expected results but these are inserted into 'SOA'!L7:CZ7. I need the IDs going down Col L from L3:L95 aligned with the relevant entry from 'Assessment'!L7:L130

I've tried simply changing to BYROW which does fill Col L but only returns a "#VALUE!" error.
My amended formula in 'SOA'!L3 is:
=BYROW('Assessment'!L7:CZ130,LAMBDA(column,TEXTJOIN(",",TRUE,FILTER('Assessment'!A7:A130,NOT(ISBLANK(column)))))).

Sorry for not explaining my use case properly; I incorrectly assumed that transposing the desired results would have little impact on the formula.

thanks in advance if anyone can help

[#5]

@Clause9 

=TRANSPOSE(BYCOL(Assessment!L7:CZ130,LAMBDA(column,TEXTJOIN(",",TRUE,FILTER(Assessment!A7:A130,NOT(ISBLANK(column)))))))

I am unsure if i correctly understand how your data is actually laid out. I've tried to replicate the layout of the data and this formula could return the expected result.

Sheet "SOA":

[#6]

Once again, thanks very much for your assistance ! Transpose worked a treat.

As background, the formula is being used in a risk assessment spreadsheet whhich now details the controls selected per risk and the risk associated with each control. These provide a direct link between risk assessment and risk treatment/security controls and help support audit and assessment of the risk process.