'Members' in Cognos Analytics - Extremely powerful and unique feature

Cognos has always had a very powerful feature called 'Dimensionally Modelled Relational (DMR)' schema. Basically, even if you are not using a pure Dimensional Database (like Transformer Cubes or TM1), Cognos allowed modelling Dimensions, Hierarchies, Levels, etc on top of the Relational Data sources.

This way it allowed the Report Authors to drag only a specific element from the dimension rather than dragging the whole column and then filtering for values. It also allowed using the Dimension functions like Children(), Siblings() etc.

This feature is also available out of box when using Cognos Analytics. In Cognos Analytics, when you create a Data Module, and specify a data item (column) as Identifier or Attribute, you can enable the 'Members' property. When you do that, Cognos will find the Unique Members or Elements from the column and show them in the tree. These 'members' can be then independently dragged on the rows or columns, essentially creating a filtered set of elements. 

Some viewers of my Cognos Analytics Video Course complained that this feature does not always work. Instead of seeing the members values, they see a list of 'NULL' texts in the members. This might be an error due to type conversion and so far I have not been able to see an exact cause why this happens for some. I will update this blog if I find more information.

Below screenshot shows the Members of Month identifier.