Program Indicators - sub-strings in filter expressions

I need to include a sub-string expression in a program indicator filter. There is e.g. no d2:left function for program indicators, but the 2.33 manual says the following:
" Tip

DHIS2 is using the JEXL library for evaluating expressions which supports additional syntax beyond what is covered in this documentation. See the reference at the project home page to learn how you can create more sophisticated expressions"

The JEXL library support operators like “=~” (embedded sub-string) and “=^” (first sub-part of string), but DHIS2 supports none of them. So I have two questions:

  1. Does DHIS2 provide any way of filtering a program indicator for a sub-string?
  2. Which sophisticated JEXL library expressions do the above paragraph in the manual refer to?

Best regards
calle

Hi Calle, thanks for reporting the issue!

@dhis2-tracker, would you be able to have a look?

Best,
Karoline