If you have the NAV Advanced Dimensions granule, you can use a dimension code in the Field or FilterField arguments of the NL function with tables that have advanced dimensions. Jet Reports creates "virtual fields" for each of the dimension codes.
Since advanced dimensions are stored in secondary tables, this feature greatly simplifies writing reports with Advanced Dimensions.
Jet Reports will add virtual fields for dimension codes to custom tables if the custom tables are designed just like the standard tables using the same secondary tables to store advanced dimensions and the same field numbers and key structures.
Virtual fields for dimension codes will not be visible in the Designer table and field lists.
If you have created an Advanced Dimension with the same name as a field in the table from which you are pulling data, Jet Reports will use the field in the table rather than the Advanced Dimension.
An example of this occurs in the Cronus database that ships with NAV. In the Sales Line table (Table 37) there is a field named Area (Field 82). In the same database, there is an Advanced Dimension named Area.
If you use "Area" in an NL or NF function that references the Sales Line table, Jet Reports will use the Area Field from the Sales Line table rather than the Advanced Dimension named Area. The simplest fix for this problem is to rename the Advanced Dimension. If you do not want to rename the Advanced Dimension, you will have to pull the data out of the table that stores the Dimension Entries instead.