How do you move an arcade type platform to Arcade?

[GiSWiG]

I like to keep things easy and for Arcade, use Retroarch FinalBurn Neo primarily and Retroarch MAME 2003-Plus and it works out rather well and easier to get working. FinalBurn Neo also covers Capcom Play Systems 1, 2 and 3. 

Importing FinalBurn Neo as "FinalBurn Neo" put it under Arcade but importing MAME 2003-Plus as "MAME 2003-Plus" created a new main platform, such as Arcade, Consoles, etc. as "MAME 2003-Plus". I found how to move games between platforms but not entire Platforms.

Thanks for any help!

[Rlad]

right click Edit>Parents, tick Arcade, untick Root.

[GiSWiG]

Cool! Thank you!