This also works via this keyboard shortcut - if you select one of the object types (e.g. a field or line etc) then press:
Option Command A
it will select all objects of the same type as the object your first selected.
Yes, I've known of the command-option-A shortcut for a long time. Has
this trick also been possible since way back when?
The benefit that I see for toolbar trick is that you don't have to
locate the object on the layout and select it. Clicking on a sub-pixel
line can be tricky without your glasses on
Thanks for the tip!