If you want to use Arrays...

Progress Summary
A28: =COUNTIF('Raw Data'!R:R,B28)

C30: =IF(ROWS(C$30:C30)>$A$28,"",INDEX('Raw data'!$A$1:A$250,SMALL(IF('Raw data'!$R$1:$R$250=$B$28,ROW($1:$250)),ROWS(C$30:C30))))
committed with CTRL + SHIFT + ENTER

copy down to say C39

As you alter B28 you should find your list updates accordingly.

Arrays if over used will affect performance of the file.