Drill Down Questions are a type of question format used to explore data or topics in a layered way—starting with a broad query and then diving deeper into specifics based on user responses or selections.
Drill down questions are helpful to:
Checkbox allows you to add the drill-down questions (also known as the cascading drop-down questions) to your surveys using a simple configuration.
Go to the Edit tab of your survey and click on “Add Question”. From the drop-down, select Drill Down Question.

This is where you configure:
It may feel a little confusing at first, but it gets much easier once you've done it a few times.
Let’s say you want to ask the user for their Country name, and based on their selection, follow up with a question asking for their City. The city options shown should depend on the country chosen in the first question.
Checkbox requires a file in a specific JSON format to enable drill-down functionality. This file must be accessible via a URL and should look like this:
Once the file is uploaded and available at a URL:
Checkbox reads the file based on property names. In the above example:
Think of it as a large circle (Country) containing smaller circles (Cities) labelled by their "name" value.

To extend the drill-down further, such as including Districts within cities, your JSON file should be structured like this:

For the original two-level example (Country → Cities), configure as:

To extend to Districts, click +Add Level, then:

Finally, here is a link to the file if you wish to construct the question based on the Country -> City properties: https://static.checkbox.com/data/countries.json or simply just practice the construction of this question type.
This section allows you to manage various options for question validation and scoring.
Checkmark this box if you want the question to be answered as compulsory. The user can not go forward from the current page unless the question is answered.
Encourages the respondent to respond to the question. The user encounters the message “An answer is recommended, but not required.” if the question is left unanswered in one attempt. Respondents can ignore the message and click “Next” again to go to the next page of the survey.
Aliases are the alternate texts or codes that you can display on your reports/exports. These values are not visible to the respondent and are helpful when you want to associate a particular value with your provided question.

This section of your question allows you to administer how your questions and your options would appear on your survey page.
Question Text Position: Lets you decide the position of your question with respect to the options. By default, it is set to “Top”. This means that the question will be placed above the answer options
Question Position: Lets you decide the alignment of the question (left, middle, right) with respect to the survey page. By default, it is set to “Left. This means that your question will be left indented.

This section of the question allows you to manage the conditional appearance of the question based on either a previous response, a contact attribute or a response property. You can combine two or more conditions using “OR/ AND” conditions by clicking on them. If you’re still unsure about how this feature works, please refer to our “Quick Start: Add a Condition to a Question”.
