Try

AL5=IFERROR(INDEX(I$4:I$24,SMALL(IF(($AG$4:$AG$24>=$AJ$5)*($AG$4:$AG$24<>"--")*(FREQUENCY(IF($AG$4:$AG$24>=$AJ$5,MATCH(I$4:$I$24,$I$4:$I$24,0)),ROW($AG$4:$AG$23)-ROW($AG$4)+1)),ROW($AG$4:$AG$24)-ROW($AG$4)+1),ROWS($A$1:A1))),"") with Control+Shift+Enter

Am5=IFERROR(INDEX(AG4:AG24,MATCH(AL5,I4:I24,0)),"") and drag down..