Yes it does. Press M, Click the Grinding Node and hover ur mouse over the ? beside the Invest Energy Bar. You can see the description. Basically Every Node Level increase Drop by 5%, up to 50% at Lvl 10. But note that the drop is applied to only 10% of the time while u grind. 

yeah level 10 node means 5% drop rate increase

Technically speaking, it gives you 5% per drop rate 10% of the time. Hence:  Lv1 - 5% drop rate 10% of the time (0.5%) Lv2 - 10% drop rate 10% of the time (0.1%) Lv3 - 15% drop rate 10% of the time (1.5%) etc etc Lv10 - 50% drop rate 10% of the time (5%)