I have this formula on Google sheets:
=ARRAYFORMULA(IFERROR(IF(ISBLANK(A2:A),SPLIT(REGEXREPLACE(C2:C,",","+VITAMIN "),"+"),SPLIT(A2:A,"+"))))
How do i remove spaces on left after my split?
You can see example in column F in this example:
https://docs.google.com/spreadsheets/d/15ZU_mUrnTvhssgHF231dHKFjjsD7t_0pEFm0ysKoL6A/edit#gid=0