Question 2D Shader mask sprite distortion

I've been messing around with shader graph trying to make an "underwater" mask effect.
The idea is that all the sprites that are behind the shader make a sinusoid movement, like if it was underwater.

I'm trying to replicate this:

https://mobile.twitter.com/therujik/status/1208035937671884800?s=12

I got everything working up to step 6, but in step 7 he adds this sinusoid effect.
I don't know how to replicate this effect with Shader Graph.
Here is what i got so far:

 

Found the solution.
Just had to create another land tile with a distortion shader and use "Sprite Mask" component in the water object to show the distorted tiles.