I see that you have the MyCad utility, with smartbom you can export the bills of materials in excel and therefore separate the parts of the trade from the screws...
For this you have to have categories assigned to your screws to the parts of the store...
For us all the parts of the trade have a property Category = Industrial Supply, to Screws and then we filter with these elements
Your customer probably has the plan/vendor (or equivalent) columns and may not agree to add properties. Just by sorting on these 2 columns, it allows you to rough up the work. Sometimes you have to replace a few lines that are at the top of the table to put them with their counterparts. It's a little tinkering that, admittedly, induces an additional risk of human error.
Should the classifications be in separate tables or simply a grouping?
What I'm going to propose is a hack but it should work. In the main assembly, you create files, screws, then commercial parts, etc., then in these folders you will put everything related to them and create assemblies of the parts in the files. This way you will have an ASM for screws and commercial parts for your bills of materials...
No need for Third-Party Tools to do it, it's quite possible with the basic functions of Solidworks (manage by a column, etc...) but you have to put the info/attribute in the files beforehand
There is also the fact of playing with orders in ASMs:
First: Manufactured Parts
second: commercial parts
third: screws (creation of a Screws folder in the ASM tree)
Then when you put a nomenclature, you check the two boxes "follow order/follow cascade order"
And as a result, you can easily segment a nomenclature into three.
It seems to me that by creating 3 models of momenclatres in Excel format with for each one a filter on a different property (Screws, purchased etc) and by inserting each of these momenclatures in a drawing, we get the desired result.
The only problem is that they cannot coexist with nomenclatures based on models in Sw format.
It should also be possible to create configurations with only the elements you want to see in each BOM (1 for assemblies, 1 for commercial parts, 1 for screws, ...) plus 1 complete and then by inserting BOMs, with different models, for each configuration.
And if you want to limit user manipulations, you need to be able to automate all this by macro, to see what are the criteria that can allow you to select the elements to put in which configuration.