This Sublime Text 3 plugin will open the side bar and focus on the current file (if there is one) when you run the command "Open Side Bar And Focus File".
It's a simplified version of Focus File on Sidebar, so you should probably use that.
You can git clone git@github.com:akrabat/OpenSideBarAndFocusFile.git from within your Packages folder.
There are no default keybindings, so you can add your own.
I use:
{"keys": ["super+shift+1"], "command": "open_sidebar_and_focus_file"},