De Minimis - How the formula know if a component is non-originating?

Summary:

In a formula like below, how system know if a component IS_NOT_ORIGINATING?

VNM=Sigma(Filter((MATERIAL+MATERIAL_OVERHEAD)*QUANTITY,IS_NOT_ORIGINATING))

Content (required):

I am trying to set up a sample BOM that passes De Minimis rule of USMCA. During the process, the mentioned formula showed up. I just took the assumption that GTM logic automatically looks at each Country of Origin of components then decide if it is originating or not. However I was wrong. When GTM calculates VNM based on above formula, it considered ALL components as Non Originating.

I am wondering if I missed any set up to indicate if a component is originating or not, besides setting 1) the country of origin field 2) partner section (regions) for USMCA