If i understand correctly, try this example
[{"id":"48fe1953.6ae07","type":"inject","z":"b779de97.b1b46","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"name\":\"tom field\",\"roomaccess\":\"room 4\",\"timefrom\":\"18:00\",\"timeto\":\"00:00\",\"mode\":\"active\",\"dayofweek\":\"0123456\",\"pin\":\"12345\"},{\"name\":\"tom field\",\"roomaccess\":\"room 4\",\"timefrom\":\"18:00\",\"timeto\":\"00:00\",\"mode\":\"active\",\"dayofweek\":\"0123456\",\"pin\":\"12345\"},{\"name\":\"tom field\",\"roomaccess\":\"room 4\",\"timefrom\":\"18:00\",\"timeto\":\"00:00\",\"mode\":\"active\",\"dayofweek\":\"0123456\",\"pin\":\"12345\"}]","payloadType":"json","x":90,"y":4360,"wires":[["860122fb.32e13"]]},{"id":"860122fb.32e13","type":"change","z":"b779de97.b1b46","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"$$.payload.$merge([$sift($, function($v, $k){\t$k != \"pin\"\t}),{\"id\":[{\"pin\":$.pin}]}])","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":270,"y":4360,"wires":[["94229627.6ff1d"]]},{"id":"94229627.6ff1d","type":"debug","z":"b779de97.b1b46","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":500,"y":4360,"wires":[]}]
