It’s already in 5.0. Group it into a node group. Give it a name and right click on the name and click mark as asset. Save it in a folder that is setup as an asset folder. Then In asset browser click the unassigned category on the left. Drag your node group into one of the 3 categories: Camera & Lens Effects, Creative, or Utilities. You will probably want to create an icon for it and add that just like any asset thru the n-panel in the asset browser. Ctrl+s to save the file and it will appear on the asset shelf in the compositor. It’s all about putting it in the right category. Note: You can actually put it any category and it will still get added to the asset shelf, but it will only be seen when you select the all at the top. you can add your category thru the 3 lines icon on the asset shelf.
