social/mail_activity_done/views/mail_activity_views.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <!--
        Copyright 2018-20 ForgeFlow <http://www.forgeflow.com>
        License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl.html).
    -->
    <record id="mail_activity_view_form_popup" model="ir.ui.view">
        <field name="name">mail.activity.view.form.popup</field>
        <field name="model">mail.activity</field>
        <field name="inherit_id" ref="mail.mail_activity_view_form_popup" />
        <field name="priority">20</field>
        <field name="arch" type="xml">
            <field name="activity_type_id" position="after">
                <field name="state" />
                <field name="date_done" />
            </field>
            <button name="action_done" position="attributes">
                <attribute
                    name="attrs"
                >{'invisible':[('state', '=', 'done')]}</attribute>
            </button>
        </field>
    </record>

    <record id="mail_activity_view_search" model="ir.ui.view">
        <field name="name">mail.activity.view.search</field>
        <field name="model">mail.activity</field>
        <field name="inherit_id" ref="mail.mail_activity_view_search" />
        <field name="arch" type="xml">
            <field name="res_model" position="after">
                <field name="done" />
                <field name="active" />
                <filter
                    string="Completed Activities"
                    name="activities_completed"
                    domain="[('active', '=', False), ('state', '=', 'done')]"
                />
            </field>
            <filter name="activities_overdue" position="attributes">
                <attribute
                    name="domain"
                >[('date_deadline', '&lt;', context_today().strftime('%Y-%m-%d'))]</attribute>
            </filter>
            <filter name="activities_today" position="attributes">
                <attribute
                    name="domain"
                >[('date_deadline', '=', context_today().strftime('%Y-%m-%d'))]</attribute>
            </filter>
            <filter name="activities_upcoming_all" position="attributes">
                <attribute
                    name="domain"
                >[('date_deadline', '&gt;', context_today().strftime('%Y-%m-%d'))]</attribute>
            </filter>
        </field>
    </record>

    <record id="res_partner_view_search_inherit_mail" model="ir.ui.view">
        <field name="name">res.partner.view.search.inherit.mail</field>
        <field name="model">res.partner</field>
        <field name="inherit_id" ref="mail.res_partner_view_search_inherit_mail" />
        <field name="arch" type="xml">
            <filter name="activities_overdue" position="before">
                <filter
                    string="Open Activities"
                    name="activities_open"
                    domain="[('activity_ids.active', '=', True)]"
                />
                <filter
                    string="Completed Activities"
                    name="activities_completed"
                    domain="[('activity_ids.active', '=', False), ('activity_ids.state', '=', 'done')]"
                />
            </filter>
            <filter name="activities_overdue" position="attributes">
                <attribute
                    name="domain"
                >[('activity_ids.date_deadline', '&lt;', context_today().strftime('%Y-%m-%d'))]</attribute>
            </filter>
            <filter name="activities_today" position="attributes">
                <attribute
                    name="domain"
                >[('activity_ids.date_deadline', '=', context_today().strftime('%Y-%m-%d'))]</attribute>
            </filter>
            <filter name="activities_upcoming_all" position="attributes">
                <attribute
                    name="domain"
                >[('activity_ids.date_deadline', '&gt;', context_today().strftime('%Y-%m-%d'))]</attribute>
            </filter>
        </field>
    </record>

    <record id="mail_activity_view_tree" model="ir.ui.view">
        <field name="name">mail.activity.view.tree</field>
        <field name="model">mail.activity</field>
        <field name="inherit_id" ref="mail.mail_activity_view_tree" />
        <field name="arch" type="xml">
            <field name="date_deadline" position="after">
                <field name="state" />
                <field name="date_done" />
            </field>
            <tree position="attributes">
                <attribute name="decoration-muted">state == 'done'</attribute>
                <attribute
                    name="decoration-danger"
                >date_deadline &lt; current_date and state != 'done'</attribute>
                <attribute
                    name="decoration-success"
                >date_deadline == current_date and state != 'done'</attribute>
            </tree>
        </field>
    </record>

    <record id="mail_activity_view_calendar" model="ir.ui.view">
        <field name="name">mail.activity.view.calendar</field>
        <field name="model">mail.activity</field>
        <field name="inherit_id" ref="mail.mail_activity_view_calendar" />
        <field name="priority" eval="2" />
        <field name="arch" type="xml">
            <field name="summary" position="after">
                <field name="state" />
                <field name="date_done" />
            </field>
        </field>
    </record>

</odoo>