I tried it on the server action side, and here’s what I could come up with:
Created a set value with dummy JSON data.
Created another set value with junk data & save.
Open the SA in code view and change the value of second set value as shown.
This is the output:
There is an issue since past two/three version with the server side SET VALUE and custom text/html/bindings etc, so you cannot add ["{{data}}"]directly in the UI.
Although, in this particular case, I don’t think set value support being set as an array like, generally. So code view is the only option.