I am unsure if this is a question regarding Photoshop or Illustrator but can anyone offer guidelines on how this image was created for the text to be behind part of an image but not all? Example image attached.
I would do that by having a clipping mask on the text based on the shape of the hill in the foreground.
Three layers.
Background layer is desaturated version color image to provide b&w structure
Layer 1 Type Layer
Layer 2 Same as Background image but full color values and mask to reveal layers below
Attempting your method I have come up with this, not quite right though.
If you are referring to my response, and looking at your layers panel
The bottom layer should be a desaturated version of the full color image, and in your image, it is in full color.
The type is in color. Different, but no problem
The top layer should be full color with a conventional mask. No clipping mask required.
Apropos of covering part of a type line, I often warned my students to be very careful because you can come up with some unintended results as seen in the now famous cover of California's WHERE magazine
Gmez, you made a B&W layer on top, clipped to your text. So the B&W only shows up where the text is. I think it actually looks good, but it's not what you were intending to do. There are a couple of ways to do it. An easy way is to just rasterize your text layer, then put a mask on it (not a clipping mask) and paint out what you don't want. But this method is destructive, so if you want to change the type later you're SOL. For this, considering that you want the background desaturated anyway, I would just duplicate the base layer, put it on top, put a layer mask on it, and paint out the background so the text pops through where you want. It involves a little more masking, but if you do it that way then you can just put a desaturation layer below it, and now your foreground will be fully saturated and cover the text, while the background is desaturated.
Edit - scratch that, I guess you can put a layer mask on a text layer without rasterizing it. Learn something new every day. Just do that, paint out (with black) whatever you don't want on the text layer mask.
As to the desaturation. Try using an adjustment layer instead. It's non-destructive (you can reverse or alter it later) and takes less space in your final file (good practice for later when things get more complicated). Click on the bottom layer, then add a Hue/Saturation adjustment layer, and move the saturation down. Now on the mask on that layer, paint the foreground black to bring back the color. There are better ways to get black and white (that give you more control over your contrast and 'colors'), but hue/saturation is a good first step.
Edit: That magazine cover is hysterical.