To display a subset of partners from your action, you need to perform the following steps:

1. Add an action for non-French speaking customers:

<record id="action_my_customers" model="ir.actions.act_window"> 
    <field name="name">All my customers who don't speak French</field> 
    <field name="res_model">res.partner</field> 
    <field name="domain"> 
        [('customer', '=', True), ('user_id', '=', uid), 
         ('lang', '!=', 'fr_FR')] 
    </field> 
</record> 

2. Add an action for the customers who are customers or suppliers:

<record id="action_customers_or_suppliers" 
        model="ir.actions.act_window"> 
    <field name="name">Customers or suppliers</field> 
    <field name="res_model">res.partner</field> 
    <field name="domain">['|', ('customer', '=', True), 
                               ('supplier', '=', True)]</field> 
</record> 

3. Add menus that call these actions. This is left as an exercise for the reader.