Yeah, that’s a pretty old post with some old concepts when glide was a lot more limited. In my example, I had separate sheets for each test type because they were vastly different. I have since restructured that part quite a bit to only use one sheet. The goal back then was to point to different sheets with different layouts, but make it look like one list. I think the other people had wanted to use the same sheet, but still have different layouts. Since then we have gained the Independent Screen Layout option, which allows you to design the details screen for each list item independently, but can become a problem if you list is dynamically changing, since you would have to go into the editor to redesign any new list items. You could do something similar to what I did with tiles, but you would only be able to achieve one tile per row. You wouldn’t be able to have two columns for tiles.
Personally, if I’m understanding what you want, you should actually be using the tiles as you have them, then create a relation from that city table to an category table that lists all of the categories of attractions for each city. Then you have a relation in that category table to an attractions table that lists each attraction. In the details of each screen, you just add an inline list that displays the data from the relation column. That would honestly be the easiest way to do it and you can see an example of it in the Multi-Level Select demo in https://concepts.glideapp.io/. It’s an old app and I haven’t updated it for a long time, so a lot of stuff in there uses some old methods. You could maybe shortcut things a little bit, and instead of having a category repeated for each city, you could maybe could use a custom action to write the selected city to a user specific column somewhere, then refer to that user specific column to build a template column in your categories sheet that will join the city name and category to create a relation to the attractions sheet, which would have a template of the city and category. There’s several ways to approach it depending on how compact you want your data, or how you want it to flow.
Overall, I think this thread may not completely apply to what you are trying to do.