Restrict Lead documents based on field lead owner

I am trying to restrict leads to certain owners only.
For example based on lead_owner
Right now it works only for creator. which is very different from what i need to achieve.

They are all working on same territory.

Sales managers add leads, and other leads come in from different places.
The assignment logic works.

I want to only allow docs which are by the certain field.
How do i do this?

I am using frappe cloud to host erpnext right now. v13

Can i create a new Owner Document. which links the owner to the doc?
And can i add restrictions to the Linked document that they can only see if its them?

Thank you in advance