I have implemented the tutorials (parts 1 and 2 of the series) and it is working fine for me.
My immediate guess as to why it is not working for you is because you probably did not whitelist the bl_get_terms_from_filter_categories function which was not a thing when the tutorial was written. See Filter: bricks/code/echo_function_names – Bricks Academy and Whitelisting echo functions in Bricks 1.9.7 and above - BricksLabs.
I can take a look inside and help you fix if you want.
You may contact me via support@brickslabs.com.