As far as I understand you would like to send each parameter to different Airtable fields, right?
Indeed, it isn’t possible to dynamically change the field of the hidden field, but if you want to differentiate each parameter in different field here is what I would personally do:
I would create a hidden field to send the parameter to one filed in Airtable
I would create Formula filed for Facebook, Instagram, Commercial and use IF formula for each of them with the following logic:
If Hidden field is Facebook, show Facebook on the Facebook formula field, else show empty cell.
If you need more detail on how Airtable IF formula works, please check out this article.
What I am trying to do is a referral system.
The problem is that if I have 200 referrals with their affiliate code doing marketing campaigns I can’t have traceability of who has registered on the platform because of their link.
Is there any possibility that a hidden field can be added in a variable way.