Firstly, it's not a good idea to mix code and data folder. The two should be completely separate, so that your code can work regardless of the location of the data (on the local drive, on a usb drive, on a remote server, in the cloud...)
Secondly, it's not clear what you mean by "available". Matlab can access data in any folder and can easily list the content of any folder with dir. e.g. if you wanted to know all the .csv files in a specific folder you'd use:
folder = 'C:\somewhere\somefolder'
filelist = dir(fullfile(folder, '*.csv'));
%process the files one by one:
for fidx = 1:numel(filelist)
data = readtable(fullfile(filelist(fidx).folder, filelist(fidx).name)); %read the file
%... code to use the data
end
