Root Explorer is the best file manager for user ROOT. You will have access to all the files for android system.
Features include support for multiple tabs, Google Drive, Box, Dropbox and network (SMB), Viewer SQLite database, Text Editor, creating and extracting files zip, tar or gzip, rar, multi-select, scripting files, search, reassemble, permissions, markers, sending files (by email, bluetooth, etc), view thumbnail images, Viewer binary XMLAPKchange owner/group files, creating symbolic link, ability to “Open with”, MD5, shortcutting.
What’s new in version 3.3.2
-A few more quick fixes
-Fix for new Lollipop SD write code
-Allow write to external SD without root Android 5.0 in Lollipop
-Display is Linux context in file / folder properties (Android 4.3 +)
-Change is context menu option (Android 4.3 +)