How do I change the project structure from flat in this case?

I have a project where I upload images with sprite.variable&".png" how do I indicate the path with myfolder/ ??

"myfolder/"&sprite.variable&".png"

It doesn't work, it doesn't show me the image as before, in this case the variable is from a family, I don't know if it makes any difference from the normal sprite.

"myfolder/"&sprite.variable&".png"

thanks, I tried again today and it worked, I think yesterday I had put the initial letter of the folder lowercase, while in the game it was uppercase... but now I still have a problem, the variable in question can vary its contents, and I have many folders, if it indicates in the path of a folder, it excludes the contents of all the others, I could remove all the files from the folders but the organization would be affected, isn't there a way to indicate a generic folder?