Need help with a random research roll for a game

So I'm making a board game for me and my friends. I'm going to have a companion app to go along with it. In the game there's a research system that you can spend points on. There's a level 1, 2, and 3 research. The higher the level, the greater the range of researches you get (later ones being better but costing more and having the chance of getting a cheaper one still).

My method for revealing the research that the player got is by making a list when the app initializes that is simply numbers 1-28 (the number of researches in the game). Then I roll a number when they pay for the research. All of the researches are simply hidden text boxes and the number you roll corresponds to making one visible.

So here is the problem, the button currently isn't doing anything and I don't know why. I also don't know how I could filter the research the player gets by what level of research they're at. I have 3 checkboxes for level 1, 2, and 3. Level 1 research is numbers 1-10, 2 is 11-20, and 3 is 21-28. If you know a solution to either of these problems I'd be really grateful if you could help me.

Sorry this is so much information, I'll happily clarify anything in the comments.

This looks like a case of multi-select.
Some examples: