[M5Rick]

The red circled one is the engine cooling reservoir and needs top up with 50/50 mix BMW a/freeze and de-ionized water to the bottom of the pipe,torch may help here.
You topped up the blue circled which is the turbo intercoolers reservoir so you need to remove the engine cover carefully and check the 4 small turbo coolant hoses for leaks and replace using new hose clips.It's an M5 weak spot but easy to fix. It gets very hot there above the turbos and even with the heat sleeves in place they do eventually fry. As an additional protection I put a piece of folded thick oven foil underneath the hoses fixed with thin wire.