If you want to remove or hide Bootstrap buttons / Bootstrap-Components / Bootstrap toggle button (tinymce buttons) from WP Post Editors. There are two ways to do this:

1. If your site is not using Bootstrap, then you can disable it by going to WordPress dashboard >> Settings >> General >> Bootstrap loading >> This site is not using Bootstrap CSS — please see screenshot:
https://d7j863fr5jhrr.cloudfront.net/wp-content/uploads/2017/06/540112-Bootstrap.png?x36781

2. If your site is using Bootstrap, then you can disable it by adding following code in the theme’s or child theme’s functions.php file to remove Bootstrap buttons from editor:

add_filter( 'mce_buttons_3', 'remove_bootstrap_buttons', 999 );
function remove_bootstrap_buttons($buttons) {
return array();
}

add_filter( 'mce_buttons', 'remove_toggle_button', 999 );
function remove_toggle_button($buttons) {
$remove = array( 'css_components_toolbar_toggle' );
return array_diff( $buttons, $remove );
}