Filter based on Unique Values that only match certain criteria

This may be beyond my skill level in Google Sheets, and it's certainly straining my brain to think through, but I have two columns out a large spreadsheet (30000 lines or so) that I need to find matches between unique values on one list, and non-unique but specific values ONLY on another list. That is, I would need the following list to return only the values on the left that had a 3 in the right column every time that value appears on the left, not just for a specific instance.

I have the following formula from another couple answers mocked up, but it doesn't get me all the way there:=UNIQUE(FILTER(A2:A,B2:B>0))

How can I get it to exclude the ones that have, for instance, both a 2 and a 3 in the right column for the same value in the left column?

Edit: To put it in more real terms (I was trying to keep it abstract so I could understand the basics), I have a Catalog ID and a Condition for items, and need to find all Catalog IDs that only have Good copies, not any Very Good copies. This link should show what I want to achieve: https://docs.google.com/spreadsheets/d/e/2PACX-1vSjenkDS2Mk3t4kTcDoJqSc8AV6ONu4Q17K1HPaIUdJkb7dhdnbAt-CzUxGO3ZoJISNpGajUtFTGz8c/pubhtml?gid=0&single=true

to return only the values on the left that had a 3 in the right column every time

try:

=UNIQUE(FILTER(A:A; B:B=3))

update 1:

=UNIQUE(FILTER(Sheet1!A:A; Sheet1!B:B="Good"))

update 2:

=UNIQUE(FILTER(Sheet1!A:A, Sheet1!B:B="Good", 
 NOT(COUNTIF(FILTER(Sheet1!A:A, Sheet1!B:B<>"Good"), Sheet1!A:A))))