@Shrotter I am also facing similar issue- Issue

I want reference to the part from instance - shown in red block.

From above answer, I get oSel.Count2 = 0.

if TypeName(oProductdocument) = "ProductDocument" then
'Search for products in active node
oSel.Search "CATAsmSearch.Product,in"

    if oSel.Count2 <> 0 then
        'first selected product is the active node
        Set oActiveProduct = oSel.Item2(1).LeafProduct

Thanks in advance