You will need to add the following line to the Fallout4Prefs.ini file above the section marked [Launcher]:
 
bEnableFileSelection=1
 
You will need to change the following line in Fallout4.ini:
 
sResourceDataDirsFinal=STRINGS\, TEXTURES\, MUSIC\, SOUND\, INTERFACE\, MESHES\, PROGRAMS\, MATERIALS\, LODSETTINGS\, VIS\, MISC\, SCRIPTS\, SHADERSFX\