Sorting Wordtracker data

[SCW]

I am new to Wordtracker and  would like to call upon experienced users to help me with sorting data.

Lets say I have developed half a dozen niches from a single top-level category or seed keyword. What approach do you use to pull all of the data together and eliminate overlapping keywords from the separate niches? Do you combine all of the exported csv's into one spreadsheet first?

Thanks for your input!