Sidebar Page Hierarchy Wotchamaflips

Greetings

Can anyone please help?

I am trying (100% failing so far) to rein in how the sidebar page hierarchy works on a WP site I’ve recently inherited.

Without getting too wordy: my goal is to have a sidebar hierarchy which will, on any given page, show ONLY its parent page and its fellow children pages and nothing else.

The site has a number of “Parent” pages – covering different topics, naturally Taking 3 topics – parent pages like this:
1) Colors, 2) Airplanes and 3) Animals from the Jungle

AT THE MOMENT the Sidebar hierarchy is a shambles, something like this (on EVERY page):

AIRPLANES
737
757
Concorde
Jumbo Jet
ANIMALS IN THE JUNGLE
Tigers
Monkeys
Zebras
Rhinos
COLORS
red
yellow
green
purple
orange

It’s a disorganized mess…..

Now, I don’t see why it should be so hard – indeed why it should not be intuitively easy – for the WordPress interface to allow me to arrange things so that the “AIRPLANES” page(s) show the “AIRPLANES” items in the sidebar (and nothing else) and same again with the “COLORS” page(s) etc.

Easy it’s not, though… Can anyone please help me?

I have by the way found something which LOOKS like a possible answer:

https://www.metaltoad.com/blog/wordpress-tutorial-unique-dynamic-sidebar-each-page-or-not

– if anyone has experience of this I’d appreciate it – particularly as I have no experience of editing .php files. (All well and good the author writing “insert this into your .php file” – great! – but WHERE in the file? Any advice on that please?

I’ve waffled enough – thanks for any help or advice, whether it involves .php or not.

D