I implemented a model that inherits from 'mail.thread' and in the form view I want to show only the "message_ids" that are of the type 'comment' and also that this session is visible for a given state of that model. This is part of the code I am talking about.

this is my .py

class ModelModel(models.Model):
    _name = 'myModel.myModel'
    _inherit = ['mail.thread']

    STATE_SELECTION = [
        ('draft', 'Draft'),
        ('open', 'Open'),
        ('closed', 'Closed'),]

    name = fields.Char(string='Name')
    state = fields.Selection(string='Status', selection=STATE_SELECTION, default='draft')

....

this is my .xml

<record model="ir.ui.view" id="model_model_view_form">
    <field name="name">myModel.myModel.view.form</field>
    <field name="model">myModel.myModel</field>
    <field name="arch" type="xml">
        <form>
            <header>
                <field name="state" widget="statusbar" statusbar_visible="draft,open,closed"/>
            </header>
            <sheet>
                <div class="oe_title">
                    <div class="oe_edit_only" states="draft">
                        <label for="name"/>
                    </div>
                    <h1><field name="name" class="oe_inline"/></h1>
                </div>
            </sheet> 
            <div class="oe_chatter">
                <field name="message_ids" widget="mail_thread"/>
            </div>
        </form>
    </field>
</record>

to apply domain try with this:

            <div class="oe_chatter"> 
                <field name="message_ids" widget="mail_thread" domain="[('message_type', '=', 'comment')]"/> 
            </div> 

to hide/show this part try with this:

            <div class="oe_chatter" attrs="{'invisible': [('state', 'in', ['draft', 'closed'])]}" > 
                <field name="message_ids" widget="mail_thread"/> 
            </div>

but none of this resulted.

Thanks