Idea Summary
The default behavior of the left navigation menu is not user-friendly.
1. The user has to click on “>” at the end of the list menu item to expand or collapse it.
2. when it's expanded, would be better to keep it expanded for that specific sub-menu, so we can see the list current entry selected

Use Case
Each time user want to expand/collapse the left navigation sub menu.
It will be easier and simpler to click on the item label to expand/collapse the sub menu

Preferred Solution (Optional)
Steps

• Go to Global Page (Page 0).
• Create a dynamic action on page load.
• Action : JavaScript and paste below given code.

$("#t_TreeNav").on("treeviewactivatenode", function(e, ui) {
    var n$ = $(e.originalEvent.target).closest(".a-TreeView-content");
    if (ui.nodes.length > 0 && ui.nodes[0].link === "") {
        if (n$.parent().hasClass("is-expandable")) {
            $(this).treeView("expand", n$)
        } else if (n$.parent().hasClass("is-collapsible")) {
            $(this).treeView("collapse", n$)
        }
    }
});