The scope of variables remembered by a "remember" trigger are Global. That is why their values are overwritten if the trigger is executed in more than one market.
But because of the order the variables are parsed in MF Pro (see manual, chapter Triggered Betting - Reference - Variables - The Order of Parsing Variables), you can attach other variables to their names.
If you want to distinguish between the markets, you can add market_id to the end of the remembered variable name, so in your case it would be bcsels_market_id, and when you will be referring to a particular selection you will be writing, for instance, bcsels_market_id_1_sel_order.
If you want to remember variables separately for each match, you can add market_parent_id (this was also the old way of creating triggers for multi-market football strategies): bcsels_market_parent_id.