Hi @didate,
I’ve just tried it with the last android version (2.4.1) and it is working fine. This is the expression I’ve used:
d2:right(d2:left(V{current_date},7),2)
V{current_date} will return a date with the following format: yyyy-MM-dd. So the inner d2:left will return the first 7 characters from the left yyyy-MM and then the d2:right will return just MM which is what you are trying to achieve.