The lines you see in your image are called banding.
An image doesn't only have a resolution when it comes to its dimensions. It also has a bit depth which can be seen as the "resolution" of the color values. Banding occurs when this "resolution" forces the steps between colors to be so large that the image cannot create the illusion of a smooth gradient.
This can happen if an image has a low bit depth (like an image in Indexed mode, a gif or png), or if you manipulate an ordinary (8-bit and more) image further than its bit depth allows. You "stretch out" color data at a certain "resolution" to have a larger span and a kind of "pixelated" effect occurs. Much like what happens if you scale an image up, but with the colors instead of the dimensions.
Sometimes I've had banding problems using some of Photoshop's adjustment layers and found that I could achieve what I wanted using a similar tool. For example Hue/Saturation where I used Channel Mixer instead and the problem disappeared.
In your case you need to either remove/change the adjustments that cause the issue or smooth out the colors of the banded layer by somehow adding some data where it's missing. The two basic tools for that is:
Experiment with applying these effects (maybe multiple times) with different settings and in different order. (I would turn the image into a Smart Object to make it easier.)