1) Flatbush is just one neighborhood, as is Midwood, Sheepshead Bay, Kensington or any other area.
2) Flatbush which is almost all black, was once white and very Jewish, that was pre-1960.
3) Midwood is the area that roughly is between Ave. I – Ave U, Ocean Parkway to Nostrand, this area may be called Flatbush, especially by older folks, but it is, Midwood. (Midwood was it’s own city at one time, separate from Brooklyn).