Filtered selection lists in forms is harder to explain than to demonstrate. Look at the video below for a quick example.
As you can see, the choices presented for Job Title change based on the selection made for Department.
This has two major advantages. First, it’s far easier for your user to make an appropriate selection (i.e., does not have to look through ALL jobs to find one appropriate for the department). Also, for the doc maker it provides a level of validation and control where users can only make correct choices.
How does this work?
Primary & Secondary Category Table
Start off by making a simple table with primary category and secondary categories of information that will be used in the filtered lookup. In this case, the primary category is Departmentand secondary category is Job Title). They can be found in the table
Next, create a table that will be used to store all responses to your form. This table will receive all of the choices and data entered by your form user. In this case, I simplified the form to only show the two columns necessary to demonstrate a filtered lookup. Refer to the table
Creating the form is very straightforward however, because you are looking up information from another table, you have to make an update to the privacy settings for the lookup to work as expected. See the video below for how to change these settings.
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Remember, if you want to play with this doc and look at the tables and formulas, here’s a button to