In the list component, it does not seem to have a direct way to create a sublist from a list. there is a 'select list item: list-index' function, it will be great if the index parameter accepts a list or you can add additional sockets to make it possible.
P.S. These blocks can be dragged directly into your Blocks Editor workspace.
See A way to group projects by theme
for a demo.
That would work, but in a general way, so far i feel that the list component is missing such an important function to make a sublist from a list unless i missed sth in the methods there (like i did with the 'split first' thing:). BTW, you are awesome in providing answers to my questions___orz
Why do you need such function, because in an easy way you can achieve it. That's why it is not enabled. You can you make a list or join block to take multiple items from various list at a time.
If not simple you can make a procedure
Not sure I agree with that, sublist is a common need in my opinion.
Maybe you need some SQL-like functions you can use with tables (lists of lists)?
See https://docs.google.com/document/d/12t4HLNRepCnbmcfycdF8wSHWht_D1P8hKJpTknVDChY/edit?usp=sharing
If that's useful, I also have an EQUIJOIN somewhere.