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 itemsg: Update org-imenutab: Fold/unfold item+/-: Increase/decrease depths-tab: Fold/unfold all itemsspace: Show current itementer: Go to current item
