(Unless you are writing a total conversion (TC) mod), you should never add someone else's DLL to you own mod as a) you are now incompatible with any other mod that adds a DLL, b) you have to update your mod every time the 3rd party DLL mod is updated and c) your mod has unnecessary "bloat" - what you should do is make your mod "depend on" the 3rd party DLL mod, which you do from the "Associations" tab in ModBuddy (and the two pieces of information you need for my DLL mod are "DLL - Various Mod Components" and "d1b6328c-ff44-4b0d-aad7-c657f83610cd")
You then need to EITHER make you own mod also depend on the enabling mod OR add ALL the files from the enabling mod (in this case "Global - City Working Distance" to your own mod.
A city has three ring boundaries - work, buy and acquire - in the standard game these are 3, 3, and 5 respectively.