Comparing two datasets and find matching features

Could you post a workspace with some sample data? Might make it easier to give some suggestions. Would be helpful to see the data structure as it sounds like it might be better to explode the lists into features and process with the needed logic, then re-make the lists if needed.

Are you looking for an exact match between the two datasets? I might consider concatenating the attributes, on both tables, then using the FuzzyStringComparer, it will produce a figure telling you how good the match is.

I would use an InlineQuerier for this after exploding the lists

Select t1.*,t2.csv_line_number as matched_t2_line 
from 
"Table1" t1,
"Table2" t2
where 
t1."from"<=t2."from" and 
t1."to" >=t2."to"

This will give you the matched row from the first table, and the line number of the matching row from the second table. 

If I didn’t want to explode the lists, I’d always resort to working with python as FME is fairly limited with working with lists