ExecuteCurrentActionAgainOnce is tightly coupled to rest calls to external services.

See Documentation:OCLOperators_RestPost

Its main usage is when a RestPost has failed, and you suspect that the reason for failure is a lapse of an accesstoken valid time. You would then want to silently use the refreshtoken to get a new accesstoken - and once you have the accesstoken you want to ExecuteCurrentActionAgainOnce from a special column named onfail in the nesting for the call parameters.