Changing the format of nested xaxis ticks labels for the boxplot chart

Question

I want to change the format of the nested xaxis ticks labels for boxplot chart (major, group and subgroup in terms of bokeh.models.CategoricalAxis attributes).

The following code is based on https://holoviews.org/gallery/demos/bokeh/boxplot_chart.html

import holoviews as hv
from holoviews import dim
hv.extension('bokeh')

from bokeh.sampledata.autompg import autompg as df
title = "MPG by Cylinders and Data Source, Colored by Cylinders"
boxwhisker = hv.BoxWhisker(df, ['cyl', 'origin'], 'mpg', label=title)
boxwhisker.opts(show_legend=False, width=600, box_fill_color=dim('origin').str(), cmap='Set1')

I want to change the format of the nested group-axis ticks labels (cyl-level).

If I change figure.xaxis.formatter the major axis (origin-level) format is changed:

from bokeh.plotting import show
from bokeh.models import NumeralTickFormatter
figure = hv.render(boxwhisker)
figure.xaxis.formatter = NumeralTickFormatter(format="000")
show(figure)

But I can't find the attributes (or any other way) to change group-axis ticks labels format (cyl-level). Smth like figure.x axis.major_label_orientation for major-axis ticks label orientation and figure.x axis.group_label_orientation for group-axis ticks label orientation.

Maybe this problem requires a very specific (custom) solution, for example pass x_range parameter while initializing bokeh.plotting.figure(x_range=bokeh.models.FactorRange(...)) (seen on https://docs.bokeh.org/en/latest/docs/user_guide/basic/bars.html#nested-categories ). Also I read that categorical ranges is sequences of strings (here). So I have to convert my dataframe columns for xaxis as strings in the format I need.