Other than the regular Bubble tutorials I’m don’t know off hand any specific resources that explain this.
But from what you’ve posted so far it’s not clear exactly where the issue is you’ve having, and without knowing your app in more detail I can’t really give any specific guidance.
But, as I said before, the inputs themselves hold their values until you reset them, so there’s no particular need to complicate things by creating additional custom states - you can reference the input values when you need them (i.e. when you create your database object).
The same applies to a RG’s list of things - once it’s set it stays set until it’s either reset, or changed.
So, for simplicity, lets say you have 2 datatypes
A Material has a name and list of Fibres
A Fibre has a name
You can set the Material name in your ‘Name input’
Then you can open a popup, select Fibres from a dropdown, and add them to a repeating group list.
Then when you’re finished, run a workflow on a button click to create a new Material with the Name being the value of the Name input, and the list of Fibres being the Repeating Group’s list of fibres.
If you want to store different percentages for the fibres on each material then you’ll need to create a 3rd datatype, that connects a material to a fibre, as well as having a field to store the percentage, but the overall process is the same.
You can make it as simple or as complex as you like, but as long as you don’t reset any inputs or clear any RG lists, all the data will be there ready to create the new database entry at the end.
Then, just clear the inputs and RG lists and you’re ready to go again.