Unable to search for network files using Finder

Hi all,

i am using SMB NAS system. However i am unable to search for files directly in its folder? I can only locate the file in the "network" tab but not the direct network file itself. Any idea whats wrong? I dont want to be wasting time spending mins to search for the entire network drive when the file can be find in secs.

[Re-titled by Moderator]