File Browser Filtering is wrong. It shows srm, and jpg files in the list. to show just zip.
To Fix:
Connect RG 300 to PC over USB Port.
NAV to I:\.gmenunx\sections\emulators where I is drive of root OS sd card.
smsplus_retrofw.default.retrofw
The files in here are not shortcuts. Open directly in Notepad.
E:\_GAMES\RG300\Stock\OSRootSDCard\apps\gmenu2x\sections\emulators
There is a selectorfilter row
selectorfilter=.sms,.bin,.gg,.zip,.rom,.sg,.col,.ggsms
selectordir=/media/mmcblk1p1/roms/ggsms/sms
https://github.com/retrofw/retrofw.github.io/wiki/Emulators-and-Apps
GMenuNX
https://github.com/retrofw/retrofw.github.io/issues
https://github.com/retrofw/retrofw.github.io/issues/79