How to write a record rule based on user's manager? (odoo11)
I want to write record rules for the module I wrote... But I'll illustrate the problem with the following example.
Suppose in the module Purchase Agreement that have a field : Responsible (relation: res.users)

I want to define record rule that every manager will only see requests from users who are their managers.
(This indicates the relation between employee and department and manager in the HR module.)

but field(responsible) in the "purchase agreement" form is related with the res.users object!

How do I get it from the user field to its manager?

One way is to add the department field in the form purchase agreement and add a domain that each user will only see the departments they are a member of.
( <field domain="[('member_ids.user_id','=',user_id)]" name="department_id"/>

so, after user select from wich department does it request: I get manager of this department with record rule.

now you can help me find the best way?

I'm looking for a way to write permissions and record rules to all modules in my bussiness.