So I tried this and it stops at the first instance of an item... I need to find all instances where it matches Z5. Can anyone help?

=IFERROR(INDEX('F2019'!J:J,MATCH($Z$5,'F2019'!K:K,0)),IFERROR(INDEX('C2019'!J:J,MATCH($Z$5,'C2019'!K:K,0)),IFERROR(INDEX('ATV2019'!J:J,MATCH($Z$5,'ATV2019'!K:K,0)),IFERROR(INDEX('RV2019'!J:J,MATCH($Z$5,'RV2019'!K:K,0)),""))))