"I coluldnt think of how to start...."
If you want to sort something, the best place to start is to read the sort documentation. Then you would learn that sort has a second output argument, which are indices that you can use to sort any other arrays that you want:
[cash.bb,idx] = sort(cash.bb)
x_loc.xx = x_loc.xx(idx)
y_loc.yy = y_loc.yy(idx)
Note: having separate structures named x_loc and y_loc does not seem to be a very efficient way to arrange your data.
