If one Dissolves by the field "SubRegion" the results from the field "Sub_Regi_1" will be lost. For example, in the table image posted, Dissolving all of Sub_Region = 1 will essentially collapse the 4 records to one.
One potential way to get around this is to do any calculations before doing the Dissolve. You could iterate through the values of "SubRegion" (using Modelbuilder or Python) and do the necessary calculations, the results of which could be placed in new fields. Then do the Dissolve. You may have to join back the table with your calculations to the feature class result of the Dissolve (using "SubRegion" as the key).
Chris Donohue, GISP