Hi,
Linked videos store fully qualified file names internally, but there is no way currently to access it in the snippets. However, you can change the material name to a string that encodes the fully qualified file name somehow. You can not use the path characters in the material names but, for example, they can be replaced by underscores, like:
C_MYVIDEOS_video593_avi
This material name can be then accessed in the snippets by the 'Selected Item' property of the Video Player element.