One formula way without helper :
1] It is generally use INDEX/SMALL to return Nth occurrence.
In F2, array formula ( confirm enter with pressing SHIFT+CTRL+ENTER 3 keys) copy down :
=IF(C2="","",INDEX(B$2:B$7,SMALL(IF(A$2:A$7=D2,ROW(A$2:A$7)-ROW(A$2)+1),LEFT(C2))))
2] It is a bit complicated use VLOOKUP to return Nth occurrence.
In G2, array formula ( confirm enter with pressing SHIFT+CTRL+ENTER 3 keys) copy down :
=IF(C2="","",VLOOKUP(D2&LEFT(C2),IF({1,0},A$2:A$7&COUNTIF(INDIRECT("A2:A"&ROW(A$2:A$7)),D2),B$2:B$7),2,0))
3] Please see attached file
Regards
Bosco