Thanks. Your suggession worked to get the report out. However, I am looking for a solution using either LOD or using a formula or someother way without making temp tables. Because, my data set has more than a million rows and growing every day. Making two tables as suggessted by you would be difficult going forward.
First calculation -> to give the consumer names for a specific advertiser.
Second calculation -> to give the brand names purchased by the consumers resulted by first calculation, across all advertisers.