Updating param from member object

Hello, I’m learning how to use panel and param.
I’d like to understand what it the best way to handle a case like the following.
I have a parametrized object (Visualizer) having members of type ItemPlot (bokeh figures). One member is called item_plot.

The plot is clickable and I’d like to change the Visualizer.item param by interacting with the item_plot member.

import param
import panel as pn
from bokeh.plotting import figure
from bokeh.models import ColumnDataSource, ResetTool, TapTool

data = {"x": [0, 1, 2, 3, 4], "y": [5, 6, 7, 8, 9]}

class Visualizer(param.Parameterized):
    item = param.Integer(default=1, bounds=(1, 5))

    def _update_itemplot_active_item(self, *events):
        for event in events:
            if event.name == "item":
                self.item_plot.active_item = event.new

    def __init__(self, dataset, **kwargs):
        self.param.watch(self._update_itemplot_active_item, ["item"], onlychanged=True)
        self.item_plot = ItemPlot(dataset)

    def view(self):
        return pn.Column(self.item_plot.view)

    def view_params(self):
        return pn.Column(self.param)

class ItemPlot(param.Parameterized):
    active_item = param.Integer(default=1, bounds=(1, 5))

    TOOLS = [TapTool(), ResetTool()]

    def __init__(self, dataset, **kwargs):
        self.source = ColumnDataSource(dataset)

    def _select_callback(self, attr, old, new):
        print(old, new)
        if new:
            self.active_item = new[0] + 1

    def view(self):
        self.plot = figure(tools=self.TOOLS)
        self.plot.scatter("x", "y", size=20, source=self.source)
        self.source.selected.on_change("indices", self._select_callback)
        self.source.selected.indices = [self.active_item - 1]
        return self.plot

visualizer = pn.template.MaterialTemplate(title="My Visualizer")
vis = Visualizer(data)

If I change the Visualizer.item param through the slider, the selected item in the plot is changed correctly (thanks to the watcher).
Also, if I click on the plot, it updates the selected item thanks to the TapTool and the _select_callback.

But what I’d like to achieve and I cannot, is updating the Visualizer.item param from the ItemPlot object.
What is the cleanest way to achieve this?