Say, I have a worksheet that has Column A for work orders, Column B
for parts

A work order may contain many parts on different rows:

Column A Column B
WO123 PN5
WO123 PN6
WO123 PN7
WO121 PN9
WO122 PN4
WO122 PN7
etc

I want to automatically "look up" a work order and "import" the parts
used into another worksheet - to create a "flat/horizontal" statement
like "WO122 used PN4 and PN7". How do I do this?