I filtered out Product Information, which removed all items that have Product Information applied. My selection was, therefore, reduced from 13 to 1 item.
I removed this filter and filtered out Basic Information. My selection is now removed to 10 items.
Out of those, I selected three items with the mouse. My selection is now three items (3 out of 9 editable out of 10 items total are selected).
Every edit on the right applies to the three items.