Filterable_Sortable_MultiSelect_python_linked.py

import panel as pn
pn.extension()

labels = [t[0] + t[1] + t[2] for t in zip('abcdefghijklmnopqrstuvwxyz','bcdefghijklmnopqrstuvwxyza', 'cdefghijklmnopqrstuvwxyzab')]
options = dict(zip(labels, range(len(labels))))

multi = pn.widgets.MultiSelect(options=options)
sort = pn.widgets.Button(name='▼', width=40)
filt = pn.widgets.AutocompleteInput(options=list(options.keys()), placeholder='Filter')

def sort_options(event):
    reverse = not event.new % 2
    multi.options = {k: multi.options[k] for k in sorted(multi.options.keys(), reverse=reverse)}
    multi.param.trigger('options')
    sort.name = '▼' if not reverse else '▲'

def filter_values(event):
    multi.value = [v for k,v in multi.options.items() if event.new in k]

sort.param.watch(sort_options, 'clicks')
filt.param.watch(filter_values, 'value')

result = pn.pane.Str()
multi.link(result, value='object')

pn.Column(pn.Row(sort, filt, margin=0), multi, result)