My boss asked me to make conditional list fields for a portal, that when I choose a value in a field, I can choose its own options in the other field. For example:

 

There are too many products, with diferent suppliers.

What I want is to can choose a supplier in the "supplier" field in a portal row, to then choose in the "product" field all the products that sells the specific supplier.

 

I still don't have acces to the DB to view the tables.

See the attached example. 

widgets.fmp12.zip

I dont have FMP12 .-.

Sorry, I should have noticed that on your profile.  Try this attached file instead...

 

The key is to setup a relationship graph that provides a table of suppliers and their related products. Also you will need value lists for "Suppliers" and "Widgets of supplier".  The first value list shows all suppliers, whereas the 2nd is limited to related records from the context of the PO line item. 

Widgets.fp7.zip

Thanks, I'll try