hello in this tutorial we will create a dynamic relation between X fields, this feature is call "Master field"

We will create 2 fields : Car Brand, Car

1 create a select field (works on select, select multiple, radio and checkbox) : name Car brand
Add value : Renault, Peugeot, Dacia

2 add a second field, multi select for exemple : Car name and select master field "Brand car"

Now when you create value in field you can "link" value in this field to master field value

Now you have a linked value fields