String operation find letter in a word that are repeating

We can count the repeating chars by following:


we did an uppercase, just for egalizing the chars for being case insensitive

with a split mentioned by @Shubham_Varshney you are prepared to handle multiple words if it is needed. For this also we would suggest to adopt the flow and let produce a report table e.g. with following cols:
Word, RepeatedChars
Madam, MA