Complex sentence: The Boers set up their laager camp in what is now the Greyville race course area being more open where suitable grazing was available to the oxen and horses, and as far as possible from the foraging hippos in the bay.
Split into simpler sentences: The Boers set up their laager camp in what is now the Greyville Racecourse area. This was chosen because it had suitable grazing for the oxen and horses and was far as possible from the foraging hippos in the bay.