I had been given three different herbicide layers with some overlapping data. My goal was to create a feature class which grouped polygons based on their treatment year. Merging all three herb layers together and then dissolving them based on treatment year got me approximately 40 different polygons, all with their own treatment year. Since some areas were treated with herbicides more than once, some polygons overlap one another. What I would like to do is group areas based on the number of treatments they have received. I have large polygons that were treated in one year and then a small polygon within the larger polygon that was sprayed again. I would like to have two polygons: the small polygon with a treatment amount of 2 in the attribute table and a large polygon minus the small area with a treatment amount of 1.