That is not possible with single-select fields, but you could do that by changing both of your fields into linked record fields, and then you could use Airtable’s dynamic filtering feature.

However, Airtable has made this very complicated to setup, and it has to be setup for your ENTIRE BASE — not just the form itself. So anywhere you see those fields in Airtable, they will have the dynamic behavior attached to it. And as mentioned above, BOTH of your fields will need to be linked record fields.

Instead, your much easier & much better option for doing this is to use Fillout’s advanced forms for Airtable.

Fillout makes the setup process MUCH easier than Airtable, and you would only need to turn your second field into a linked record field (instead of both fields). And your linked record field can work differently on your Fillout form than how it works in your base.

You can read more about this feature here: How to select and filter Airtable linked records in a dropdown.

Fillout is 100% free, and it offers hundreds of features that Airtable’s native forms don’t offer, including the ability to dynamically filter a linked record field on a form, update Airtable records using a form, create custom PDF files from a form submission, accept payments on forms, pre-fetch dynamic data from an Airtable record, display Airtable lookup fields on forms, create new linked records on a form, add a login page to your form, perform math or other live calculations on your forms, collect signatures on a form, create multi-page forms with conditional paths, connect a single form to dozens of external apps simultaneously, add CAPTCHAs to your form, and much more.

I show how to use a few of the advanced features of Fillout on these 2 Airtable podcast episodes:

• Using Fillout to create an eSignature approval process with PDF file creation.
• Using Fillout to create an order entry form with line items.

Hope this helps!

If you’d like to hire the best Airtable consultant to help you with anything Airtable-related, please feel free to contact me through my website: Airtable consultant — ScottWorld

I would like this feature as well. 
I have a production database and want to filter so that when a production is chosen, the user can then choose the appropriate season. 
Hoping this is available soon. Thanks.

2024 update:

This feature is now available with Airtable’s linked record fields.

You can also get this feature with Fillout’s advanced forms for Airtable.

Fillout is 100% free and offers hundreds of features that Airtable’s native forms don’t offer, including the ability to update Airtable records from a form, display Airtable lookup fields & Airtable rollup fields & Airtable attachments & formulas on forms, dynamically & conditionally filter linked record fields by any values that you would like, perform math or other live calculations on your forms, accept payments on forms, create multi-page forms with conditional paths, create new linked records on a form, display as many fields as you want to see in a linked record selection list (including attachments), connect a single form to dozens of external apps simultaneously, limit the number of linked records that can be chosen, upload an unlimited amount of attachments simultaneously, add CAPTCHAs to your form, add choice matrixes to your forms, direct integration with hundreds of apps like Calendly & Google Maps on your forms, and so much more. 

This feature is also available with Noloco’s advanced interfaces for Airtable, but that is an extra monthly expense. I recently gave a webinar on Noloco entitled Building a Client Portal on Noloco powered by Airtable.

Hope this helps! If you’d like to hire an expert Airtable consultant to help you with anything Airtable-related, please feel free to contact me through my website: Airtable consultant — ScottWorld