Black lives matter all black lives including the lives of people in Africa. I would like to think that the BLM movement recognize that Black lives matter everywhere including to most oppressed places and people.
I would also hope the movement sees that racism is just a branch of the ridiculous class system and a hierarchical hereditary and a monarchy are causes of this equality not solutions. You cannot (unless you are an hypocrite or dangerously ignorant) defend old fashioned racist class systems if you stand for equality and justice.
It is also important to remember that black people are not the only oppressed people in the world. USA, UK, China and Europe are wealthy “developed” nations and yet many people in these nations are living in poverty. In Britain the poorer classes and many disabled have been victims of cruel benefit cuts and a cruel system in general that is designed to humiliate and pressurize.
I hope the point of BLM is ALL LIVES MATTER.