Hey guys,
In the image below, I’m trying to make a node group. I’d like to expose the circled parameters to the node group, but there’s no plug in the GUI to grab.
How do I expose these parameters?
if you mean exposing the parameters as input sockets, than the answer is no!
you can still rebuild(I mean ‘‘mimic’’) those nodes with the help of node groups, and a bit of logic building work…
for example, in the Mapping node, one can do change the location by adding two vectors (with VectorMath), or scale with mixRGB set to multiply. For rotations you’ll need to decompose the vectors and treat every axis separately with math nodes based on matrixes.
the color ramp could also be made…but with much more work for a generic type. But using some mixRGB’s and some logic, you may achieve the functionality you need.
Exactly.
Here’s a veeery useful video to understand how it works:
Thanks for the video - very useful 
Well, It’s a bummer that Blender can’t just expose those params. Not everyone can figure out how to build a B-spline … and I’m sure those nodes already have the computations optimized.