cooperative-market/beesdoo_project/views/task.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record model="ir.ui.view" id="beesdoo_project_task_view_form"> 
        <field name="name">beesdoo.project.task.view.form</field>
        <field name="model">project.task</field>
        <field name="inherit_id"  ref="project.view_task_form2" />
        <field name="arch" type="xml" >
            <field name="user_id" position="before">
                <field name="author_id" />
            </field>
            <field name="user_id" position="after">
                <field name="reviewer_id" />
                <field name="tester_id" />
            </field>
            <notebook position="inside">
                <page string="Linked Tasks" name="link_tasks">
                    <field name="link_task_ids" />
                </page>
            </notebook>
        </field>
    </record>
</odoo>