I have created a new security group.

 <record id="real_estate.group_user_base_pricing" model="res.groups">
    <field name="name">User Base Pricing</field>
    <field name="category_id" ref="real_estate.module_category_real_estate"/>
    <field name="comment">the user will have the access to the Real Estate Management System Price List</field>
</record>

Here's the python fields. I want to apply security group on "pricing_policy" if this is equals to 'unit_base'

pricing_policy = fields.Selection([
    ('area', 'Area Base'),
    ('unit_base', 'Unit Base'),
],default='area')
area_base = fields.Boolean(default=True)
unit_base = fields.Boolean(implied_group='real_estate.group_user_base_pricing')
​

@api.onchange('pricing_policy')
def _onchange_pricing_policy(self):
    if self.pricing_policy == 'area':
        self.area_base = True
        self.unit_base = False
    elif self.pricing_policy == 'unit_base':
        self.area_base = False
        self.unit_base = True

This is the field I want to make visible when above condition is right.

<page string="Particular" autofocus="autofocus">
    <field name="pricelist_line">
        <tree editable="bottom">
            <field name="size_id" options="{'no_create': True, 'no_open': True}"/>
            <field name="category_id"/>
            <field name="unit_inventory_id" groups="real_estate.group_user_base_pricing"/>
            <field name="sector_id"/>
            <field name="starting_date"/>
            <field name="end_date"/>
            <field name="price"/>
        </tree>
    </field>
</page>

Any help would be appreciated.