两列 取非空白 不重複 (8879)

L4 {=IFERROR(INDIRECT(TEXT(SMALL(IF((C$4:J$15<>"")*(COUNTIF(L$2:$L3,C$4:J$15)=0)*(MOD(COLUMN(C:J),7)=3),ROW($4:$15)/1%+COLUMN(C:J)),1),"!R0C00"),),"")