I've seen ranges set up like this. They are trying to save space and money by having only one backstop and have only one firing position. It can be safe if it is carefully designed, but it's tricky to make everything work. I've been at one that had a single firing line and a single backstop/berm at 300yds with targets at 100, 200, & 300. If you shot prone at a target at the 100yard line, there was a good chance your bullets would go over the berm. Shooting from other positions at the closer targets introduced the possibility of having bullets hit the ground before they reached the berm.
Both of those things are, very obviously, very bad.
To make it work, you need a very tall berm. You may also need bullet baffles set up near the firing line to limit the trajectory and help insure that all bullets strike the berm.