Problem description & analysis:
The Excel table below is ordered by column A, whose values are strings separated by “-”. The first part of column A represents the category.

Task: Store the table as multiple tab-separated txt files according to different categories. The file name format is Group_Category.txt.
Group_AA.txt

Group_BB.txt

Group_CC.txt

Solution:
Use SPL IDE to execute the code:

=T@b("data.xlsx").group(#1.split("-")(1);~).(T@b("Group_" / #1 / ".txt": #2))

Explanation:
The T()function reads files as a table and writes a table to files; @ b means that column names are not included. group() function groups rows according to the specified rule and retains the detailed data in each group; ~ is the current member of the sequence, and #1 is the 1st column of the table.