I coped your sidenav samle.  I want the accordion in it with the links to be expanded.  So I have 2 questions:

1. How to make all nodes expanded on dom ready?
2. How to have just one node expanded?

Here is what I got within the SideNav

<ul class="collapsible collapsible-accordion">
                 <li id="errors-main">
                     <a class="collapsible-header waves-effect arrow-r font-size-large"><i class="fas fa-exclamation-triangle font-size-small" ></i>&nbsp;Errors<i class="fa fa-angle-down rotate-icon"></i></a>
                     <div class="collapsible-body">
                         <ul>
                         
                             <li>
                                 <a id="list-errors" href="#" class="waves-effect"><i class="fas fa-table"></i>&nbsp;List</a>
                             </li>
 
                         </ul>
                     </div>
                 </li>
                 <li>
                     <a class="collapsible-header waves-effect arrow-r font-size-large"><i class="fas fa-code-branch font-size-small"></i>&nbsp; Deployments<i class="fa fa-angle-down rotate-icon"></i></a>
                     <div class="collapsible-body show">
                         <ul>
                          
                             <li>
                                  <a id="list-deployments" href="#" class="waves-effect"><i class="fas fa-table"></i>&nbsp;List</a>
                             </li>
 
                         </ul>
                     </div>
                 </li>
                 <li>
                     <a class="collapsible-header waves-effect arrow-r font-size-large"><i class="fas fa-users font-size-small"></i>&nbsp; App Users<i class="fa fa-angle-down rotate-icon"></i></a>
                     <div class="collapsible-body">
                         <ul>
                           
                             <li>
                                <a href="#" class="waves-effect"><i class="fas fa-table"></i>&nbsp;List</a>
                             </li>
 
                         </ul>
                     </div>
                 </li>
                 <li>
                     <a class="collapsible-header waves-effect arrow-r font-size-large"><i class="fas fa-user-friends font-size-small"></i>&nbsp;System Users<i class="fa fa-angle-down rotate-icon"></i></a>
                     <div class="collapsible-body">
                         <ul>
                             <li>
                                 <a href="#" class="waves-effect"><i class="fas fa-plus"></i>&nbsp;Add New</a>
                             </li>
                             <li>
                                 <a href="#" class="waves-effect"><i class="fas fa-table"></i>&nbsp;List</a>
                             </li>
 
 
                         </ul>
                     </div>
                 </li>
                 <li><hr style="border:1px solid rgba(255,255,255,0.6);" /></li>
                 <li>
                     <a class="collapsible-header waves-effect arrow-r font-size-large"><i class="fas fa-desktop font-size-small"></i>&nbsp;Software<i class="fa fa-angle-down rotate-icon"></i></a>
                     <div class="collapsible-body">
                         <ul>
                             <li>
                                 <a href="#" class="waves-effect"><i class="fas fa-plus"></i>&nbsp;Add New</a>
                             </li>
                             <li>
                                 <a href="#" class="waves-effect"><i class="fas fa-table"></i>&nbsp;List</a>
                             </li>
 
 
                         </ul>
                     </div>
                 </li>
                 <li>
                     <a class="collapsible-header waves-effect arrow-r font-size-large"><i class="fas fa-clock font-size-small"></i>&nbsp;Releases<i class="fa fa-angle-down rotate-icon"></i></a>
                     <div class="collapsible-body">
                         <ul>
                             <li>
                                <a href="#" class="waves-effect"><i class="fas fa-plus"></i>&nbsp;Add New</a>
                             </li>
                             <li>
                                 <a href="#" class="waves-effect"><i class="fas fa-table"></i>&nbsp;List</a>
                             </li>
 
 
                         </ul>
                     </div>
                 </li>
             </ul>

Thanks in advance.