Hello! 

I would like that in the sales invoice lines only appears the value added tax (VAT) but the other taxes as withholdings only appear in the summary at the end of the invoice. 

The way Odoo Studio calls this field is as follows:
',' .join (map (lambda x: (x.description or x.name), line.invoice_line_tax_ids))

Could you include a filter that only captures taxes that are on that line that have a label such as VAT?

Exmaple:

ProductsPrice Qty Tax Total 
product a $10 1 VAT19% $10
product b $15 2 VAT19% $30

Subtotal $40

VAT 19% $7.6
-WT 2.5% ($1)
Total $46.6

Thanks

Odoo V12"

Odoo Studio