Hi. This solution no longer works for V17. I get this error

Inherited view cannot have 'Groups' define on the record. Use 'groups' attributes inside the view definition

Any Ideas? Thanks.

I was able to figure it out. For anyone in my situation, I achieved this in odoo17 by first creating a new user group that inherited from existing user that can edit the field and created a new view like this.

<xpath expr="//sheet/notebook/page/field[2]/tree/field[@name='price_unit']" position="attributes">
<attribute name="groups">purchase.group_purchase_user</attribute>
</xpath>

<xpath expr="//sheet/notebook/page/field[2]/tree/field[@name='price_unit']" position="after">
<field name="price_unit"
readonly="1"
groups="new_module.new_group,!purchase.group_purchase_user"/>
</xpath>

Notice that I now have 2 price_unit fields.

I believe this works because since the new group inherits the existing group, we have to explicitly specify that the inherited group is not allowed to view this new price_unit field. Hence, !purchase.group_purchase_user