Can somebody tell me the syntax for...

[Hexsplosions]

1. Limiting something to only specific member groups
2. Returning a member name (the member who is logged in)

I knew how to do this on 3.4.8 but I'm not a coder and I'm having trouble figuring it out.  

[-FP]

{{if \IPS\Member::loggedIn()->inGroup( array(x, y, z) )}}
Your code limited to x, y and z user groups.
{{endif}}

Where array(x, y, z) defines the user group IDs, if you want it for single member group, then replace array(x, y, z) for the member group id.

To get the name of the logged in member, I think you can just use {member="name"}

[Hexsplosions]

Thank you @-FP, I'll give it a try.

[Hexsplosions]

Worked!  

[-FP]

Nice!