how to make a data series?

(Edit: I found what this is called: a data series.)

I have a list of companies with details including number of employees, yearly revenue, industry segment, etc. I need to show these in groups, perhaps with a dropdown menu or something similar.

I need to break employee size options into 4 groups: 0-100, 101-500, 500-1000, and 1000+

And I need to break revenue into 4 groups as well: 0-400million, 4mil-1billion, 1-3billion, and 3billion+

What is the best way to do this in excel? It would be good if it was something easy to modify.