Hi Shreya Doodipala,

I hope you are doing well,

If you hide specific use security group hide in user form so you need add like below way in Odoo18.

you can use this method through hide specific group from user from

@api.model
def get_application_groups(self, domain):
    # Overridden in order to remove 'Show Full Accounting Features' and
    # 'Show Full Accounting Features - Readonly' in the 'res.users' form view to prevent confusion
    group_account_user = self.env.ref('account.group_account_user', raise_if_not_found=False)
    if group_account_user and group_account_user.category_id.xml_id == 'base.module_category_hidden':
        domain += [('id', '!=', group_account_user.id)]
    group_account_readonly = self.env.ref('account.group_account_readonly', raise_if_not_found=False)
    if group_account_readonly and group_account_readonly.category_id.xml_id == 'base.module_category_hidden':
        domain += [('id', '!=', group_account_readonly.id)]
    group_account_basic = self.env.ref('account.group_account_basic', raise_if_not_found=False)
    if group_account_basic and group_account_basic.category_id.xml_id == 'base.module_category_hidden':
        domain += [('id', '!=', group_account_basic.id)]
    return super().get_application_groups(domain)

reference odoo 18 addons/account/models/res_users.py.

Thank you.