Goto the following folder and find the installed boost library folder. I paste mine as an example folder path;
/usr/local/Cellar/boost/1.67.0_1
You need to find the most recent boost folder. If not there, you should install the boost library via brew
brew install boost
I'm assuming that you are using Xcode for your project. After the preceding steps, you need to add correct boost folder paths to your Xcode project. Open your Xcode project goto "Header Search Paths" and add the boost folder's parent folder path. Check the screenshot that I attached (ss-1 ss-1).
e.g. /usr/local/Cellar/boost/1.67.0_1/include/
for the Header Search Paths (ss-2 ss-2)
Also, you need to add Library Search Paths in your Xcode project.
e.g. /usr/local/Cellar/boost/1.67.0_1/lib/
for the Library Search Paths (ss-3 ss-3)