You use the BA Field Selection window to select fields when you are defining related tables, measures or dimensions in a cube in Business Analytics.
The contents of the window depends on what you are using it for. If you have selected a fact table and clicked Related Tables, Select Fields, for example, the window displays fields in the fact table, and the tables that they are related to.
If you are selecting measures for the cube, the window lists all of the amount fields in all the tables in the cube.