I was able to export all my BrickLink BAM Want List for 2017-2019 into XML format. I compressed them and made them available to download below.
In the remarks, I added the Year, Quarter, Column, and description
Example 2019 Q4 3 Legs
This inventory item is from the Q4 of 2019 its the legs for the 3rd Group of items for 2019 Q4
I borrowed the import instructions from a Reddit post:
Link to the Reddit Post
Link to Bricklink Import files. EDIT Found a few errors, They are fixed.
To upload an XML file to a Bricklink wanted list, you need to first open the XML file in a text editor, copy its contents, and then paste it into the Bricklink "Upload Bricklink XML format" area. This will add the parts list to your chosen wanted list. Here's a more detailed breakdown:
Open the XML file: Locate and open the XML file containing the parts list. It's recommended to use a plain text editor like Notepad to avoid potential formatting issues.
Copy the XML content: Select all the text within the XML file (Ctrl+A or Cmd+A) and copy it (Ctrl+C or Cmd+C).
Navigate to Bricklink: Go to the Bricklink website and log in to your account. Navigate to the "Want" section and then to the "Upload" page.
Choose XML format: Select the "Upload BrickLink XML format" option, which is usually the second option.
Paste and proceed: Paste the copied XML content into the designated area. Then, click "Proceed to verify items".
Verify and add: Review the items on the verification page. If everything is correct, click "Add to wanted list".
I hope this saves you some time.
Shawn