So if you now have 1 item of interest in lb1 and select 2 rows from lb2, you'd have to duplicate the value as another record from lb1 and pair each instance of lb1 with a different value from lb2. However, if you also choose 4 rows from lb3, which of the 2 values do you duplicate from lb2 to pair with the additional records required for lb3? Or are you intending to enter each into the same field, because I see you have one or more multi value fields in your table. Not many of us here would use mv fields. I for one wouldn't be able to help you do that since I won't use them (unless I was forced to) and have no idea as to how to accomplish that.
If I'm off base here, then maybe more information about the desired result would be a good idea.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.