multi-locations - products only in one store; but with multiple locations within.
Sometimes you may only want to select product from within one location.
Select the location you are interested in from the drop down at the top of BRM.
Then when you select your categories it will only pull in products that match that location:
Please Note - if you want to look at the locations of all your products then go into
select your categories and it will show you which location they are in: