Is there a way of returning a column value based on data in an array in Google sheets?

Question

Below is an image of my source data. I am using Google Sheets. It has student names in Column A, and the groups that they have signed up for in the rest of the table:

I am trying to look for all instances of each group in the array, and then return all of the names linked to that group. Please refer to the image below for what I'm after.

Final table:

I have used the FILTER function to do something similar with just a column, but am stumped to apply the same logic to an array.

Answer 1

Update

Assuming your data is on a tab called 'data', like this:

I've created another tab for the solution.

On the solution tab, you can paste the following formula into cell A1 to dynamically get all of your Groups (as headings):

=arrayformula(transpose(query(unique(flatten(data:B,F)),"where Col1 is not null",0)))

It assumes data on the data tab is in columns B to F ( data:B:F )). You can extend F to whatever it needs to be.

Then we have the query on the solution tab, in cell A2:

=query({data:$B,$B:data;$A:$A,data:$C;$C:data,$A:$A;data:$D,$D:data;$A:$A,data:$E,$E,data,$A:$A;data!$F:$F,data!$A:$A},"select Col2 where Col1 matches '"&A$1&"' order by Col1,Col2",0)

The query range is in {} . Note the , and the ; within the range.

, is a new row, ; is a return. The range is column B with column A to the right, then a return and column C with column A to the right, then a return and column D with column A to the right, etc. If you need to extend the column range, add ;data:$N,$N:data!$A:$A within the right } where 'N' is the next column letter.

There is a query on this dataset that selects Col2 from the dataset (Names), where Col1 matches the value in cell A1 (Group 1).

You can drag this formula to the right, from cell A2 to B2, to C2, to D2 etc. The only thing that changes whilst dragging is where Col1 matches '"&A$1&"' changes to where Col1 matches '"&B$1&"' to where Col1 matches '"&C$1&"' etc.