Since there is no shortcut assigned to P by default in DaVinci Resolve 14, we must resort to the next best thing ⌥ + P which adds a parallel node to your clip while in the Color Panel.
What is a Parallel Node?
'{A Parallel Node} lets you apply two or more overlapping adjustments at a single stage of a node tree.' - pg. 894 DaVinci Resolve Reference Manual.
To better understand this, Blackmagic provides a nice visual explaining how parallel nodes work similarly to additive light theory:
Compare the Parallel Mixer Node Structure to the Layer Mixer Node Structure which as the name implies, layers the nodes instead of mixing them.