I found answers to this question but they are outdated: https://www.odoo.com/forum/help-1/question/how-to-open-one2many-form-view-of-the-correspondent-line-in-tree-view-112388

I have 2 classes:  Buildings class and Rooms class. The buildings class contain a one2many field called rooms (so that a building can contain multiple rooms)

I want to show in the view form of the building a list of rooms of the building and in each line a button to open the room form. I managed to show the button but how do I tell the button the right (the one that was clicked) room to open ?

I have an example that doesn't work for me

class Buildings(models.Model):
    _name = 'my_module.buildings'    
    name = fields.Char()
    rooms = fields.One2many('my_module.rooms', 'building_id')

class Rooms(models.Model):
    _name = 'my_module.rooms'    
    name = fields.Char()
    building_id = fields.Many2one('my_module.buildings', required=True)
    
    # this method should open a form for the clicked room
    def open_one2many_line(self, context=None):
        return {
            'type': 'ir.actions.act_window',
            'name': 'Open Line',
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': self._name,
            'res_id': context('active_id'),
            'target': 'current',
        }

The view.xml file

<record id="building_view_form" model="ir.ui.view">
    <field name="name">my_module.buildings.form</field>
    <field name="model">my_module.buildings</field>
    <field name="arch" type="xml">
        <form string="Buildings Form">
            <sheet>
                <group>
                    <field name="name"/>
                    <field name="rooms">
                        <tree>
                            <field name="name"/>
                            <button
                                string="open"
                                type="object"
                                name="open_one2many_line"
                                context="{'default_active_id': active_id}"
                                >
                            </button>
                        </tree>
                    </field>
                </group>
            </sheet>
        </form>
    </field>
</record>