Set layer color based on other layers

[Krikor]

Possibly I must not have understood the question well.

Having the original image duplicate it.
Create your text in a new layer above the images.
Apply a blur to the first layer of the image - the bottom one.
Apply alpha to the image in the second layer - Add alpha channel

In the text layer, apply alpha for selection;
Invert the selection - Select - Inverse or Ctrl + I.
Select the layer with the image without the blur - Second layer.
Delete the inverted selection - Edit - Clear or Delete.

Now the text layer can be deleted or removed from view.

Perhaps with Layer Modes it is possible to achieve something interesting. But you seem to want the negative color of the original image, so:

In the image below I used Colors - Invert and Colors - Value invert .