Assuming that you are trying to rank the text line item based on the A-Z or Z-A sorting, there's a workaround:
1. Create a view with the text line item as the sort (A-Z or Z-A)
2. Use the view as the source for the new import to a staging list of the text in the line item, in which the list would be sorted accordingly
3. You can create the following properties: COUNT and RANK
Formula would be COUNT = 1, RANK= RANK(COUNT, ASCENDING, SEQUENTIAL)
4. Use the Rank property accordingly with LOOKUP to the List formatted line item with the following formula FINDITEM(Staging list, text line item)
5. Create a process with Delete Action and the Import to Staging List and run it everytime the ranking needs to be updated when new text line item is updated.
Assuming that you are trying to quantify the text line item based on the number of times the text appears then you can use SUM and LOOKUP combination. You can use the Staging List approach and SUM property to count the number of times the text appears. Then use the SUM property as reference for Ranking.