Please find Example in comment :-

<record id="res_partner_salesperson" model="ir.rule">
<field name="name">res.partner.salesperson</field>
<field name="model_id" ref="base.model_res_partner"/>
<field name="domain_force">[('user_id', '=', user.id)]</field>
<field name="perm_read" eval="True"/>
<field name="perm_write" eval="True"/>
<field name="perm_create" eval="True"/>
<field name="perm_unlink" eval="True"/>
</record>

In this record rule, we are checking for currently logged user(user.id) is salesperson in res.partner(customer/Contacts),

Now current logged user will see only that records of customer in which user is selected as salesperson (In res.partner salesperson field name is user_id)

Same this, you can create multiple record rules for different models(Just change reference model and domain).
Example of sale order:

<field name="model_id" ref="sale.model_sale.order"/>
<field name="domain_force">[('user_id', '=', user.id)]</field>

Also in sale order, salesperson field's name is user_id