File splitting based on 3 parameterrs

Hello experts,

my requirement: i have to split a file based on country, then number of records, and finally based on whether records or historical or inventory.

I have done till splitting using country and number of records, ie, if the user specifies number of records, 50000, it will generate files containing 50k records.
Now the new requirement states that on top country and number of records, i need to split the file bases on historical or inventory, the data will have HIS or INV prefixed for all the records.

The user should have the ability ti split only on HIS or INV, he can specify both, HIS and INV. The logic should split accordingly.

Please assist me in this,

thanks and regards

Abhishek