this worked for me ('section_id','=',user.default_section_id.id)

['|',('section_id.member_ids','in',[user.id]),('section_id','=',False)]

Try something like:

[('section_id.user_ids','in',[uid])]

both ['|',('section_id.member_ids','in',[user.id]),('section_id','=',False)] and ['|', ('section_id','=',user.default_section_id.id), ,('section_id','=',False)] is worked to filter customer via sales teams.

and ['|',('section_id.member_ids','in',[user.id]),('section_id','=',False)] is the best filter.

but there have one issue.

when select partner in create SO, it raise error.

Access Denied

The requested operation cannot be completed due to security restrictions. Please contact your system administrator.

(Document type: Partner, Operation: read)

there may be have security conflict in those rules.

I'd tried this:

[('section_id.user_ids','in',[uid])]

and it gives me this error:

NameError: name 'uid' is not defined.

Also, trying this:

[('section_id','=',section_id.user_id)]

Gives:

NameError: name 'section_id' is not defined

So, it seems like there is no section_id for user_id

Maybe something like this would work:

'section_id','=',  'section_id' for 'member_id' of 'user_id' from 'sale_member_rel' table

but I don't know how to write this code...