Yes, the Outline icon, which opens an Outline sidebar, is correct for OP’s request.
I don’t have OG7, but I understand one can search the Outlines for specific text. But that does not work if the text is in a grouped Shape, it works for the label of the group only.
Yes, the search at the bottom of the Outline panel is legless. A more pointed way of saying that is, OG does not handle Grouped Shapes properly. “Sub-graphs” (OG term) and their expansion is a quick-and-dirty, simplistic view, not a proper hierarchic one.
For unrestricted search, use the generic search facility Command-F, and the group that it is in will be selected in the Outline view.
For better command and control of the Outline panel, get used to the hierarchic view (the other is flattened view), and use the Expand/Collapse buttons. It is not perfect (eg. your request) but it is powerful.