USB-C cannot be 'split' in that way. However, it can be daisy-chained if your monitors support that (i.e., plug monitor 2 into monitor 1, and plug monitor 1 into your Mac). That would be the best option.
Alternatively, you can get a dock which supports dual displays. Avoid the ones on Amazon in the $50-100 range, they don't actually support dual displays though they claim to (what they do is show the same image on both your external displays). Look for a dock from Brydge (Stone Pro), Elgato, OWC, Belkin or Kensington. With any of the docks, you'll still need to connect one of the displays via something other than USB-C (e.g. DisplayPort, meaning you may need an adapter). For example, with my Elgato dock I have one display connected directly via DisplayPort and the second via a USB-C to HDMI adapter (the displays are older, not USB-C).