The 'ThreeM Segment' is available for item segmentation purposes on the SSAS_KMN and SSAS_NexaRefresh data cube as column of the 'Item' and 'Products' table respectively. 

To add this attribute to an Excel or Power BI report, just browse of it in the search bar as showed here below.

Here below an example of a pivot table displaying net sales by 'ThreeM Segment' and  configured with the 'ThreeM Segment' column in the row section.