I am making a timetable system, I need to see which teacher teaches a specific class, and sometimes there are more than one.
I have tried =JOIN(", ", FILTER(OVERVIEW!$A:$A, IFERROR(SEARCH(A2, OVERVIEW!$B:$AX), FALSE)))
and =FILTER(OVERVIEW!$A$1:$A$100, ARRAYFORMULA(REGEXMATCH(TRANSPOSE(OVERVIEW!$B$1:$AX$100), A2)))
but none of this is working.
The teachers are in OVERVIEW!A:A and the classes are in OVERVIEW!B:BX along with an search sheet for this.
I have provided an example, and I am aware of the risks that come with sharing via google sheets sheet here