Hi @nic.nicolo 
Welcome to the forum!
At first glance, it may be easier to create a data type called “Country”:
Then, create new boolean (yes/no) fields for each possible column type. For example, since Routing Number is needed for US, the associated field (i.e., column) could be “Routing Number?” (type: yes/no, list: no):
For Countries that need to submit a “Routing Number”, the value of that field would be “yes” for those particular Countries. For Countries that don’t need to submit a “Routing Number”, the value of the field would be “no” for those particular Countries.
And as a second example, another field for whether IBAN is required could be called “IBAN?” (type: yes/no, list: no)
For Countries that need to submit “IBAN”, the value of that field would be “yes” for those particular Countries. For Countries that don’t need to submit “IBAN”, the value of the field would be “no” for those particular Countries. This pattern repeats for all possible pieces of information that could be required.
In this example, I’ll just use these two columns, but you would continue adding these yes/no fields for all of the possible columns. I also added a field called “Name” to store the Country’s name (e.g., “United Kingdom”, “Unites States”):
Once all of the possible fields are set up, you can manually add or upload your data from your Google Sheet in the App Data tab by clicking App Data → All Countrys
It won’t show any entries at first since we haven’t added any entries manually, or through CSV upload. In order to upload data from the Google Sheet, the app would need to be on at least the personal plan or higher (since the Hobby plan doesn’t allow for .csv upload). If you don’t wish to change the plan yet, you can manually add each entry and select “yes” or “no” from the dropdown depending on whether that piece of information is needed for that particular Country row. As you upload the data, it will begin to look similar to this (but with more columns of course):
In order to make sure only the required columns are shown depending on the selected country, your dropdown will first want to display all of the Countries in the database using this setup:
Then, create the 25 possible inputs on the page, making sure that each input and its corresponding label are grouped together using a group element:
Placing the element in a group will allow you to select “Collapse an element’s height when hidden”; this option ensures that if an input is not required for the selected country, that input group’s height will collapse which prevents extra, empty space on the page:
Also, make sure the groups further expand vertically so they are almost touching (but not overlapping with) the group beneath them (this just helps to make sure all the extra space collapses )
Last but not least! In order to make sure the correct inputs show for the selected country, you would need to add a conditional to each group element which checks to see if it is a required field for each country. For example, the conditional on the IBAN input would be:
And the conditional on the Routing Number input would be:
Since these conditionals ‘show’ the input element groups when they’re needed, we also need to make sure all of the groups are not shown by default; otherwise the groups will all be shown no matter what since we don’t have any “this element is visible → unchecked (no)” conditionals on the group elements. To do this, make sure “This element is visible on page load” is unchecked for each input group as shown here:
Here is a short GIF of how Bubble dynamically shows the correct inputs in action:
Preview link:
Editor:
And that should do it! Feel free to let me know if I can clarify anything or if you have any questions at all
Sounds great,