I have a technique which would allow you to launch off a Record, and display a list of say counties for that state and then quick select as many as you like. Each click will create a child record.
Then another click when done selecting to return to the parent record to see the children as the embedded report on the parent.
But while the technique is native, it usually takes me about an hour or so to set this up for my clients. Then you would have the technique and be able to use it for other situations. Contact me directly if you want to discuss further.
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