There are multiple ways to build conditional paths in your form:
1. Redirect to an Airtable field
miniExtensions Form has a feature called "Redirect to Airtable field". It allows you to redirect users to a URL in an Airtable field, which can be customized per user.
By creating a formula in Airtable, you can redirect users to different steps (e.g. to another form or logging them into a portal automatically using the login formula) based on their answers in this form. The field can be a formula that is made up of any logic supported by Airtable formula fields.
You can find the feature in the Submission Actions section:
Under After Submission, turn on Redirect
Set Redirect URL Source to Airtable Field.
Select the correct formula field as the Redirect URL Field.
This setting is only available when Redirect to a new form in 5 seconds and Show read-only version of record after submission are turned off.
Furthermore, it is only available for standalone forms, not child forms (i.e. forms used in a portal or shared view or for linked record fields in a main form).
You can show users their previous submission(s) by redirecting them to a formula that takes the user to a portal and logs them in automatically.
2. Conditional pages in multi-page setup
In multiple pages mode, you can skip an entire page (not just a field) based on certain conditions.