You can no longer "browse" the network from Libreelec using SMB. You must manually setup Windows 10 network shares. There are many threads here describing exactly how to do this. I was one of the first to have this problem way back in November 2017 with the release of LE (Krypton) 8.2.0
Maybe someone else can link one of the threads with instructions on setting up SMB Shares from Windows 10