These nodes are equivalents of the similarly named Nuke nodes:
https://learn.foundry.com/nuke/content/reference_guide/color_nodes/ploglin.html
https://learn.foundry.com/nuke/content/reference_guide/color_nodes/log2lin.html
https://learn.foundry.com/nuke/content/reference_guide/color_nodes/ociocolorspace.html
https://learn.foundry.com/nuke/content/reference_guide/color_nodes/ociologconvert.html
You have to check if your colorspaces are available in the default OCIO configuration (try nuke, blender or natron configs), else you’ll have to dig more.
Troy Sobotka would be able to give you a subtanciated answer, but he’s not on these forums anymore (see topic Ownership of the contents - #8 by chroma_ghost)