Table name as user filters

Is it possible to add Tables as user filters? To elaborate and as example, I have financial information (e.g. Sales, Profit) of companies in U.S.A and China in two tables called 'USA" and "China", respectively. Both the tables are structured uniformly with identical column names and data types. I would like to have a filter to let users select the country (in other words, the TABLE) first.

I don't want to merge the data into one table because number of records per country are huge. On the other hand, using Union query table may be an inefficient alternative.

As far as my limited understanding goes, if we could pass Table names as user filters, it could be great in terms of efficiency and flexibility.

If it's not possible, is there a good alternative?