Change text in a listing, and have it update a referenced text box in another window.

I would do it with automatic numbers and cross references.

In the number on the image insert a cross refence with paragraph number only.

When you add a new number between the existing, you need only update the cross reference list and add the the circle and link it to the correct paragraph. I coppied an existing and relinked the cross reference to the new paragraph.

I added an example. https://www.dropbox.com/t/FDp1i9H3oCKE92sX

I'd like to know if there's a way to highlight the number in the building listing, change the number, and have it correlate/automatically change dot's interior number?

If the goal is to change one number and get InDesign to change the other, you can use the Content Collector tool (the same feature as Edit > Place and Link) to change listing number(s) and the Update all Links button in the Links panel.

~Barb

Just brainstorming 😉

How about threading all the dots - with either static list of numbers - or ParaStyle with numbered list?

And the same on the list of buildings.

Then, when you need to add new building - just create new dot - by clicking on the outport of the previous dot / inport of the next dot - and then update list.

Or maybe footnotes - or rather endnotes option - would work better? 

But if you also need to change the colour of the dot... then probably only scripting would help.