This appears to be the crucial part that has not been obvious to me so far in my journey. I understand completely that everything is data driven from a row of information. I have worked hard to make sure I have the right info in the right places but after a month of attempting to build this app - I have only just now become aware of this.
I’m now guessing this screen is the key to getting my app to do what I want it to.
Is there a video on how all this works? What is it called? What can you tell me about it that I should know at a super basic level - remember I’m not as tecnicomolgigal as you are! 
My guess is that if I build a child spreadsheet of all 20 children options, link them to one of the three parents and then use this box to somehow say show “experiences” the app will then only show experiences children under the experiences button? Repeat at the next level to show only the grandchildren of the original parents. (The things in things video should go to the third level - it implies to the uninitiated that the principal will replicate in each level and it doesn’t. Its another concept entirely)
So
3 parents: Experiences/Plan & Learn More
20 Children: walks, tracks, toilets, cafes, murals, history
50 Grandchildren: individual walks, individual tracks, individual cafes individual etc
I am now also assuming that the individual waterfalls will be the children of waterfalls who are the children of experiences… and so on?
Can someone direct me to how to use this new-to-me part of the system please?
Really appreciate the time you are all taking to walk me through this. Ill be quite chuffed if I ever get to the end and get this working!