How can I dynamically source a field from another field? I have 2 fields called Method and Output - Method is a dropdown list field and has values 1,2,3 whilst Output is a dropdown and has values 1.1,2.1,3.1 - I want it such that if value 1 is selected as the Method, it auto populates 1.1 as Output etc... thinking of doing this without the use of a workflow or script and it automatically selects and is a stored value field? Any solutions?

You can do this by using Custom Records - see NS documentation on "dependent dropdowns". Your Output object must be a custom record so that it can have a field on it for Method. Each Output record has a value for Method. Then your custom field for Output can use the defaulting to filter by Method.