i created some groups like accountant and staff which have different field visibility and access.

In the Sale Order quotation form , I have hid the total prices,  terms and conditions, and also all necessary fields , by adding attr groups=".module_name.group_name"

but when I do the same on price_unit on the tree view in the order lines of the sale.order form , the following error is displayed

"Field 'price_unit' used in context"

how do i solve this? 

I have attached an image of what I mean.

https://ibb.co/ChQ0wQN 

I just want to hide the price_subtotal and price_unit from the order lines for all users who are staff and only show it to the accountants