alpipego

This plugin makes long and complex navigation menus better manageable by creating groups that can be expanded and collapsed.
By default, all navigation menus in wp-admin will be collapsed. When holding the Option/Alt-key while clicking, all sublevels will be expanded with one click.
For general support, please use the support forums on <a href="https://wordpress.org/support/plugin/wield-menu" rel="ugc">wordpress.org</a> 
For developers: Head over to the <a href="https://github.com/alpipego/wield-menu/" rel="nofollow ugc">Github repository</a> 
For everything else, find me on <a href="https://twitter.com/alpipego" rel="nofollow ugc">twitter</a> or slack

Wield Menu

I had this problem when working on themes demo as they have all possible page in the menu.

Thanks!

Very handy

Make long and complex Navigation Menus wieldable

James Osborne

If you’re using AMP in transitional or standard mode check the FAQ’s below, or follow the instructions in the settings tab after installing.
Features: 
<ul>
<li>Easy to setup</li>
<li>Works in AMP and non AMP</li>
<li>Fast load, optimal performing</li>
<li>Unlimited hamburger toggle color options</li>
<li>Options for rending in desktop and mobile</li>
<li>Bloatware free, non intrusive</li>
<li>Completely free </li>
</ul>

AMP Sidebar Hamburger Menu

If you're using AMP in transitional or standard mode check the FAQ's below, or follow the instructions in the settings tab after installing.

Wield Menu vs AMP Sidebar Hamburger Menu