I would prefer to separate the weights by elevation if possible. But essentially I am looking for a way to easily calculate the weight of each floor for seismic analysis.
probably the only way of isolating floor and framing for a specific floor would be to use Dynamo. Getting a bit clearer explanation of what you trying to do would certainly help in solving your question.
i.e. - I have a three story concrete structure made of concrete columns, conc beams and floors. I need to isolate the weight of each floor (framing and slab) to run a seismic calculation.
actually revit can not calculate the weights or any thing for multiple categories based on elevation or floor,
the idea of material take off is based on every category,
so i would recommend to use dynamo you may find a way to do what you want or you can calculate the weight for each category you have for example: columns,beams and floor . and thin filter it based on level, so you can get the weight of the columns in floor 2 by using material take off, then do that thing for floor and beams so at the end you can get the sum for all categories you want manually