From Product information managemen >Products>Released product Form, I can open EcoResProductDetailsExtended form.
I need to add a column with the vendor name.
As far as I see, we are using the table InventTable and a relation with the VendTable is there by default:

Going to VendTable, we can find the relation with DirPartyTable:

Now comes the part that doesn't work.
I have tried to add both VendTable and DirPartyTable to the DataSource list in EcoResProductDetailsExtended form.
VendTable with: - JoinSource: InventTable and Link Type: InnerJoin.
DirPartyTable with: - JoinSource: VendTable and Link Type: InnerJoin.
And the last thing was to drag the Name field from DirPartyTable to the grid. Seems nice but I get an empty column. What am I doing wrong ? I know I could add a display method but that not allow the user to filter on this column..