Calendar array to return unique results based on date and PO number

[jdefont]

I am trying to modify the below array to determine if a date and PO number have already been returned as a result for a date then skip to the next PO. see the attached screen capture which is returning the same PO number multiple times in the calendar.
I'm using named ranges (CalList, PO_Number) when referencing the table holding all the data.
=IFERROR(INDEX(CalList,SMALL(IF(Date=A$8,ROW(Date)),ROW(1:1))-TableRowStart,5),"")
In the screen capture "Garb" is showing up 3 times and "Stance" 5 times, and I'm looking for the array formula to determine that PO and Date has already been used in the calendar so skip to the next matching date and PO.

 

[jdefont]

I'm getting an error message but this formula seems closer to what I am trying to accomplish
=IFERROR(INDEX(CalList,SMALL(IF(Date=A$8,IF(MATCH(A$9:A$18&A$8, Date&A$8,0)=ROW(Date),ROW(1:1)))-TableRowStart,5),""))