Group related fields together

Originally Posted by Gregb11

Being on version 2022 I assume you have access to the FILTER formula. If so, in C2 try this:

=TEXTJOIN(", ",TRUE,TRANSPOSE(FILTER($A$2:$A$7,($B$2:$B$7=B2)*($A$2:$A$7<>A2),"")))

and copy down.

ty for your help!
I tryed your function but I get some errors (maybe because I got an german excel verstion) so I had to adjust it a little bit:
=TEXTKETTE(", ";WAHR;MTRANS(FILTER($A$2:$A$7;($B$2:$B$7=B2)*($A$2:$A$7<>A2);"")))

Basically it works, but there is only a comma at the beginning of the cell and the word "true". Can this still be adjusted?

Thanks!