Enable OR condition for user permission

The scenario is,

I have a Doctpye called Leads, i Need set user permissions such that only the leads which are are associated with particular users will be able to see those leads.
I have four fields, assigned_to, managed_by, referred_by and cr_assigned. If any of these fields contain the user email, that user alone needs to see the lead.
When i set the user permission for a single user, it only shows leads in which the user email is present in all four fields. i want it such that it if email is present in any one field, that lead should be shown to the user?

Thank you for your assistance in advance