I have 1,000's of 1km asc files which are simply named 1.. 10,000 which I wish to merge in to 5km asc files, and appropriately name with the correct OS Tile Ref. I have managed to perform a spatial filter and added the OS tile ref. I now wish to filter so all 1km tiles within an identified 5km tile go forward for merging. Is there a way to automatically filter based upon the present OS tiles without creating the individual condition filters manually?