Advance Filter with Multiple Criteria

Ok here goes. I am fairly decent with VBA, and can understand most code after looking at it for awhile even if I am unable to come up with on my own, but having spent sometime look for a solution I am struggling to find what I need .I have a large worksheet that has a couple of unique Identifiers in it. I am trying to do a advance filter or the equivalent to populate another sheet in the same workbook. On Sheet1 column A is a material number that is unique, Column L is also unique. What I am trying to accomplish is look at column A find the unique numbers copy them and paste them on Sheet2 in column A, but also look at Column L and add another row on Sheet2 with the same even if the Unique Material number is the same but Column L is Different. I am attaching a example work book of what I am trying to do.
Code I am using to Get the Unique Material Number in Column A

Sub extract()
  
With Sheet1
.Columns(256).Clear
        .Range(Cells(2, 1), .Cells(.Rows.Count, 1).End(xlUp)).AdvancedFilter Action:=xlFilterCopy, CopyToRange:=Cells(1, 256), Unique:=True
End With
End Sub

But I am at a loss as to how to combine the two Unique Columns in a search.

In the Attached workbook the 1st 2 sheets Held & Data are what I currently have come up with. Sheet3 "Desired" is what I want it to look like. I appreciate everyone's help and assistance. I hope that I with my description of my issue and the attached workbook people will understand what I am trying to accomplish.
Thanks,
qppg