Additional recommended modules: better_exposed_filters
With the inclusion or Better Exposed filters, you can configure multiple dropdown select filters, and toggle filters (using radios) for views, with sensible defaults already configured for which icons to display within the toggle buttons. Additional icons can be configured in the Toggle Button Group component \components\molecules\toggle-button-group\toggle-button-group.twig
Browser default checkboxes and radios are replaced with the help of .form-check, class for both input types that improves the layout and behaviour of their HTML elements, that provide greater customization and cross browser consistency.
Custom <select> menus need only a custom class, .form-select to trigger the custom styles. Custom styles are limited to the <select>’s initial appearance and cannot modify the <option>s due to browser limitations.
Set the multiple attribute as to get a real multiselect that uses checkboxes
<select id="example-getting-started" multiple="multiple">
Multi-select behavior with check-boxes makes use of this library: https://github.com/davidstutz/bootstrap-multiselect
Docs here: https://davidstutz.github.io/bootstrap-multiselect/