org-imenu shows a sidebar displaying the Imenu and allows the user to filter which headlines are shown using the interactive org-imenu-filter-select that uses the same syntax as org-mode search. This is very similar to org-sidebar without the org-ql dependency which means that org-imenu is probably less powerful than org-sidebar.

M-x: org-imenu

• f : Filter items
• g : Update org-imenu
• tab : Fold/unfold item
• + / - : Increase/decrease depth
• s-tab : Fold/unfold all items
• space : Show current item
• enter : Go to current item