Replace All Occurrences of a Substring in a String

you can use substitute function for this.

for example: substitute(
"ACTUAL_TEXT","SUB_STRING","TO_REPLACE_WITH"
)

Appian OOTB substitute() works fine for any basic use cases as DeepakG already mentioned above.  Just chiming in to add, that for more advanced use cases (fuzzy / pattern-matching / etc), you can also use "regexReplaceAll()" found in the Regex plug-in.

If you can check if reduce can give this the desired result also. Somewhere in community I read this last time.

if(
  count(ri!originalValues) <> count(ri!replacementValues),
  ri!inputText,

  reduce(
    fn!substitute,
    ri!inputText,
    merge( ri!originalValues, ri!replacementValues )
  )
)