Defining file pathway

I have a question regarding a very simple function which I managed to use a while ago but now cannot figure out where it was. I am preparing an experiment where I show people images, and I defined the image names in an excel file. The problem is that because I’m using over 500 images, I’ve put them into separate folders so that the study folder is not too messy. Now, I think one way to refer to the image would be to put the folder name in the excel file (e.g. pictures/apple.jpg), but I swear someone showed me a way to refer to the folder in builder view, either in the image properties or loop properties, and I can’t find it anymore. This would make my life much easier because that way I can easily change the pathway if I decide to reorganise the stimuli. Is there a way to specify where to get the pictures from? I know the excel file should be referenced in the “Image” field, but I don’t know about the folder name…
I hope this makes sense and thank you very much in advance!