Where to find it:

NodeGraph / Right Mouse Click / Add Nodes / Math / Extension Pack / M /

max returns the maximum of the two parameters. It returns y if y is greater than x, otherwise it returns x.

https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/max.xhtml

•X

Specify the first value to compare

•Y

Specify the second value to compare

•Output RGB

Separate computation for Input Channels Red, Green, Blue with an Alpha Channel of 1.0

•R

Computation for Input Red channel only, saved into R, G and B channel with an Alpha of 1.0

•G

Computation for Input Green channel only, saved into R, G and B channel with an Alpha of 1.0

•B

Computation for Input Blue channel only, saved into R, G and B channel with an Alpha of 1.0

•A

Computation for Input Alpha channel only, saved into R, G and B channel with an Alpha of 1.0