I was hoping to show the one parent they belonged to, so I had “show hierarchy” enabled. The combined effect of having both those enable is does not lead to what I would expect.
In the end, deactivating “show hierarchy” made it so only current children would be displayed, at the price of losing the parent.
When the 2 checkboxes are combined, what is displayed is a bit more like an accordion menu, something that I’m sure has it’s use case, just not what I expected based on the wording of the respective checkboxes.