@Johg_Ananda _Merge(object) is a hidden formula that’s mostly interesting due to the fact that it allows exposing internal Coda object structure. _Merge(whatever) + "" is an idiom to render that as JSON:
Then use e.g. RegexReplace:
thisRow.[Column 4].RegexReplace('^.*"identifier":"([^"]+)".*$', "$1")
to only extract the row ID.
Source: A somewhat of a documentation of hidden formulas [Added mechanics of nested buttons]
@Murray_Adcock Actually while doing this I figured out I could simply try thisRow + "". And voila, it does this:
and then just thisRow.[Column 6].Split("/").Last() to get the row ID. No hidden formulas required!
@Krunal_Sheth FYI