I have given users only 'See Own Leads' for the Sales module to control the visibility. However, this does not extend to Customers and all users can still see all customers. For this I created an additional record rule for Partners which would restrict the Customers visible to each user.

However, after this I noticed that, in cases like creating a new calendar meeting, the 'Attendees' menu which is a many2many_tag widget, fails to function properly and raises a read access error. This should not ideally be the working of the widget. When I search in the drop-down, I should see my own customers. Right now, it seems to start showing all customers, then suddenly realises that I don't have the right to view them and raises a read-access error. How can I resolve this?

Any help for a workaround to this would be highly appreciated.