If the field you wish for is not in the table related to you report - you can add the table yourself.

See 6. Wizard query for adding a table.

How do i know what table and what field name?


Right click in the field - choose Form information - Form Name

A new form pops up and under Administration you can see the table and field name


Stand on the field - right click

Choose - Personalize

The table and field name is now shown: (SalesTable).PurchOrderFormNum

How do I know which fields relate the tables?


Go to AOT (Ctrl+D)

Open Tables

Find table - Here InventTable

Open the table - open relations - find the table you want to connect to - open this - the relations are now shown