Complex sentence: Daunt Books opened its first branch outside London in Saffron Walden, Essex, under the name Hart's Books before opening a second branch outside London in Marlow, Buckinghamshire, under the name The Marlow Bookshop.
Split into simpler sentences: Daunt Books opened its first branch outside London in Saffron Walden, Essex, under the name Hart's Books. It opened its second branch outside London in Marlow, Buckinghamshire, under the name The Marlow Bookshop.