Hi Anaplan community,
I am wondering if I will be able to setup ALM if I have a SELECT clause selecting one list item of my line item subset.
You shouldn't have any issues. But you can still go ahead and replace SELECT with LOOKUP.
Create a dimensionless module and insert one line item. Format that line item on LIS that you have and pick one of items from the LIS that you want to hardcode.
As @Misbah you shouldn't have any issues as those line item subsets are not production lists, but it is still best to use Lookups. To do this, create a SYS LISS properties module with the LISS as the Applies To. Now you can use it like any other properties module.